The Battle of Inabayama Castle — A Seven-Year Conquest of Mino, and the Day Nobunaga Proclaimed “Tenka Fubu”

8th month, 1567 (Eiroku 10) | Inokuchi, Mino Province (present-day Gifu City, Gifu Prefecture)

The Battle in Three Lines

• The battle in which Oda Nobunaga captured Inabayama Castle, the stronghold of the Saitō clan of Mino, and achieved his long-cherished pacification of Mino.
• Seven years after the Battle of Okehazama, Nobunaga wore down Mino with persistence, repeating failures along the way.
• The decisive factor in his victory was the defection of the “West Mino Triumvirate.” After this battle Nobunaga raised the banner of “Tenka Fubu” and took his first step toward unifying the realm.

The Mainstream View — A Textbook-Based Explanation

Why the Battle Happened — A Grudge Spanning Two Generations Over Mino

Mino Province was a strategic point connecting the Tōkaidō and the Nakasendō, a granary occupying the northern half of the fertile Nōbi Plain. Close to Kyoto, it was an extremely important land for any Sengoku daimyō. The grudge between the Oda and Saitō clans over Mino went back to the time of Nobunaga’s father, Oda Nobuhide.

At the Battle of Kanō-guchi in 1544 (Tenbun 13), Nobuhide’s army suffered a crushing defeat at the hands of Saitō Dōsan. Nobuhide lost his younger brother Oda Nobuyasu and many troops—a severe blow. The two houses later reconciled in 1548 (Tenbun 17), and as a token of it, a political marriage was arranged in which Dōsan’s daughter Kichō (Nōhime) was wed to Nobunaga.

The turning point was the death of Dōsan in 1556 (Kōji 2). At the Battle of Nagaragawa, Dōsan was killed by his son Saitō Yoshitatsu. Just before his death, Dōsan wrote a testament addressed to Nobunaga ceding Mino Province to him. Three copies survive, and Nobunaga would use this as his justification for the conquest of Mino—the claim that “I am the legitimate successor who inherits Mino in accordance with Dōsan’s testament.”

Yoshitatsu reigned as lord of Mino for five years, but died of illness in 1561 (Eiroku 4) at the age of 35. The headship passed to his fourteen-year-old heir, Saitō Tatsuoki. Because his father Yoshitatsu died young, the youthful Tatsuoki had no time to accumulate sufficient political experience before having to face Nobunaga’s invasion.

The Full-Scale Conquest of Mino Begins After Okehazama (1560–1561)

In the 5th month of 1560 (Eiroku 3), Nobunaga killed Imagawa Yoshimoto at the Battle of Okehazama. Having thereby removed the threat to his east, Nobunaga concluded the Kiyosu Alliance with Tokugawa Ieyasu in 1562 (Eiroku 5), securing his eastern defenses. All that remained was to concentrate on Mino to the west.

In the 6th and 8th months of 1560 (Eiroku 3), Nobunaga invaded Mino but was repelled by Saitō retainers such as Nagai Toshifusa. It was a defeat that brought home to him Yoshitatsu’s strength. But in the 5th month of 1561 (Eiroku 4), receiving word of Yoshitatsu’s sudden death, Nobunaga saw an opportunity and took the field. At the Battle of Moribe he won, killing Nagai Toshifusa and Hibino Kiyozane, and he won again at the following Battle of Jūshijō. Carried by the momentum, he pressed all the way to Inabayama Castle, but could not capture the formidable stronghold and withdrew.

Years of Hard Struggle — Defeat at Shinkanō and Hanbee’s Seizure of the Castle (1563–1564)

Nobunaga’s conquest of Mino was by no means smooth. In 1563 (Eiroku 6), Nobunaga, who had attacked eastern Naka-Mino, clashed with Tatsuoki’s retainer Takenaka Hanbee at Shinkanō and was defeated. Hanbee’s ambush tactics, called the “ten-direction ambush formation,” completely toyed with Nobunaga’s army.

The turning point came from internal division on the enemy side. On the 6th day of the 2nd month of 1564 (Eiroku 7), a shocking incident occurred within the Saitō house. Takenaka Hanbee and his father-in-law Andō Morinari made a sudden assault on Tatsuoki’s stronghold of Inabayama Castle and seized it. Known as the “Inabayama Castle Takeover Incident,” this event has long been romanticized by later ages as “the act of a loyal retainer who admonished his lord,” but in recent years it is held highly likely to have been a political coup by the anti-Tatsuoki faction.

After occupying the castle for about half a year, Hanbee and Morinari returned it to Tatsuoki (or Tatsuoki gathered troops and retook it). It is also said that Nobunaga tempted Hanbee with the offer, “If you hand over Inabayama Castle, I will grant you half of Mino Province,” but the negotiation did not come to fruition. Even so, this incident impressed the Saitō clan’s decline upon those within and without, and became an occasion that accelerated the defection of its retainers.

In 1565 (Eiroku 8), Satō Tadayoshi, lord of Kajita Castle, defected to Nobunaga, and the Naka-Mino region too came into Nobunaga’s sphere of influence (the Naka-Mino campaign). To Mori Yoshinari, who had become Nobunaga’s retainer, Kanayama Castle was granted, and to Kawajiri Hidetaka, Sarubami Castle—so the absorption of the Mino kokujin advanced.

The Defeat at Kōnoshima and the Diplomatic Struggle (1566)

In the 4th month of 1566 (Eiroku 9), Nobunaga crossed the Kiso River and deployed troops at Kagamino in Mino Province (present-day Kakamigahara City, Gifu Prefecture). The two armies faced off, but Nobunaga’s army struggled against the difficult terrain and retreated. In the intercalary 8th month of that year, through the mediation of Ashikaga Yoshiaki, a candidate for shogun of the Muromachi shogunate, the Oda and Saitō clans reached a temporary reconciliation.

However, the Saitō side broke this reconciliation, and it developed into the Battle of Kōnoshima, in which Nobunaga was defeated by Tatsuoki. This became the Saitō clan’s last victory in its struggle against Nobunaga. A victory report jointly signed by the four chief retainers of the Saitō house (Andō Morinari, Hineno Hironari, Takenokoshi Naomitsu, and Ujiie Bokuzen), dated the 18th day of the intercalary 8th month of Eiroku 9, survives as the “Nakajima Monjo,” and it clearly shows that Tatsuoki was alive and well at this point. This would become a decisive source in the later dispute over the year the castle fell.

The Defection of the West Mino Triumvirate — The Decisive Moment of the Battle (8th month, 1567)

On the 1st day of the 8th month of 1567 (Eiroku 10), the decisive blow was struck. The powerful Saitō retainers known as the “West Mino Triumvirate”—Inaba Yoshimichi (Ittetsu), Andō Morinari, and Ujiie Naomoto (Bokuzen)—sent word to the Oda promising to defect and asking that their hostages be received.

Of the three, Andō Morinari and Ujiie Bokuzen held the rank of Tatsuoki’s chief retainers. For three men holding high office in the Saitō house to submit to Nobunaga together was a fatal blow to Tatsuoki. The reasons were clear:

• The youthful Tatsuoki neglected affairs of state and favored only a portion of his retainers.
• Capable retainers such as the Triumvirate had been kept away from the center of power.
• Through the long war with Nobunaga, the Saitō clan’s inferiority had become obvious to all.
• Nobunaga had absorbed the kokujin of Naka-Mino and had demonstrated opportunities for advancement.

Nobunaga’s movement was lightning-fast. While dispatching Murai Sadakatsu and Shimada Hidemitsu to receive the hostages, Nobunaga himself, without waiting for the hostages to arrive, at once gathered his troops and invaded Mino. The territories of the Triumvirate became a “free pass” that let Nobunaga’s army through openly.

The Burning of Inokuchi and the Fall of Inabayama Castle

According to the section “On the Taking of Inabayama” in the “Shinchō Kōki,” on the 1st day of the 8th month Nobunaga ran up Zuiryūji-yama, which was connected by a ridge to Inabayama Castle, and secured a position overlooking the castle town of Inokuchi. While Tatsuoki’s side was bewildered, wondering “is this friend or foe,” Nobunaga attacked all the way down into Inokuchi below the castle and put the town to the torch. That day is recorded as having been exceptionally windy, and the flames are imagined to have covered the town in an instant. The castle town was reduced to ashes, and Inabayama Castle became a “naked castle” stripped of the limbs of supply and defense.

On the 14th day of the 8th month, to surround the castle completely, Nobunaga apportioned the construction work and built a shishigaki (deer-fence palisade) around the castle. The shishigaki was a fence of logs and branches meant to prevent the castle troops from escaping. With this, Tatsuoki was completely isolated.

By this point, the fighting spirit of Tatsuoki’s side had collapsed. The castle town had burned, no reinforcements could be expected, and morale within the castle had plummeted. After about two weeks of siege, on the 15th day of the 8th month of Eiroku 10 (there are other theories; some sources give the 15th day of the 9th month), Tatsuoki surrendered and opened the castle. Tatsuoki fled along the Nagara River to Nagashima in northern Ise, and the Saitō clan of Mino effectively perished.

At the end of seven years of persistent conquest of Mino, Nobunaga at last took Inabayama Castle into his hands. The grudge carried on from his father-in-law Dōsan, the strategic objective after Okehazama, and Dōsan’s testament—all came to fruition here.

The Renaming to “Gifu” and the Proclamation of “Tenka Fubu”

Having gained Inabayama Castle, Nobunaga immediately renamed the castle and the castle town. The castle became “Gifu Castle,” and the castle town of Inokuchi was renamed “Gifu.” The “Gi” of “Gifu” is said to derive from Mt. Qi (Kizan), where the ancient Chinese Zhou dynasty unified the realm. This naming is said to have been made by Takugen Sōon, the abbot of Seishū-ji, the temple that performed memorial services for Nobunaga’s tutor Hirate Masahide.

Around the same time, Nobunaga began to use a vermilion seal carved with the words “Tenka Fubu.” Its use in issued documents is confirmed from around the 11th month of 1567 (Eiroku 10). “To spread martial power over the realm”—the meaning of these words has long been interpreted as “a declaration of nationwide unification,” but recent research has also offered more moderate interpretations, such as “restoring the shogunate’s authority in the Kinai region” or “a statement of personal resolve, like a motto.” In any case, there is no doubt that it was a turning point at which Nobunaga began to act with his sights set on the realm.

In the 9th month of the following year, 1568 (Eiroku 11), Nobunaga marched on the capital bearing Ashikaga Yoshiaki and installed him as the fifteenth shogun of the Muromachi shogunate. From the Battle of Inabayama Castle to the march on the capital was a little over a year. That he had gained the geographic and economic base of Mino became the starting point of Nobunaga’s enterprise of unifying the realm.

→ For details, see the warlord article “Oda Nobunaga.”

Multiple Theories — Exploring Possibilities from Various Angles

Theory 1: Did the Castle Fall in Eiroku 7 or Eiroku 10? (The Greatest Point of Dispute)

Regarding the year Inabayama Castle fell, there was a long-standing dispute. At first glance it appears to be a simple question of fact—”when did the castle fall?”—but behind it lies an important controversy of source criticism.

The Eiroku 7 (1564) theory — the received view of the Edo period

Most of the major war chronicles compiled in the Edo period gave the fall of the castle as Eiroku 7 (1564):

• Oze Hōan, “Hōan Shinchō-ki”
• Takenaka Shigekado, “Hōkan”
• Oda Nagakiyo, “Genealogy of the Oda House”
• “Mino-no-kuni Shokyūki,” “Mino Meisaiki,” “Do-Rui Daiki,” “Toki Saitō Gunki”

In the village registers (local gazetteers) written in Edo-period Mino and in the inscriptions of recast temple bells, the Eiroku 7 theory was also widely adopted. As local folk tradition, too, Eiroku 7 was the common version.

The Eiroku 10 (1567) theory — modern historiography

From the Meiji era onward, as historical research accompanied by source criticism advanced, decisive doubts were raised about the Eiroku 7 theory.

What proved decisive was the jointly signed letter dated the 18th day of the intercalary 8th month of Eiroku 9, preserved in the “Nakajima Monjo.” This was a document in which the four chief retainers of the Saitō house (Andō Morinari, Hineno Hironari, Takenokoshi Naomitsu, and Ujiie Bokuzen) jointly reported the victory at Kōnoshima, and it clearly proves that Tatsuoki was alive and well as lord in Eiroku 9. Because the Eiroku 7 theory holds that “Tatsuoki was expelled in Eiroku 7,” it contradicts this document.

Historians of the Meiji and Taishō eras organized this contradiction:

• Kuroita Katsumi, “Studies in National History” (1908)
• Watanabe Yosuke, “History of the Azuchi Period” (1910)
• Toki Kinsen, “Draft Gazetteer of Mino” (1915)
• Abe Einosuke, “Comprehensive History of the Two Provinces of Mino and Hida” (1925)

Through these studies, the Eiroku 10 (1567) theory became the established view in academia.

Katsumata Shizuo’s additional verification

The historian Katsumata Shizuo, in the “History of Gifu,” added verification further supporting the Eiroku 10 theory. Among the documents Nobunaga issued in the area of present-day Gifu, if one sets aside the “Jōzai-ji Donation Letter” dated the 15th day of the 9th month of Eiroku 7, which requires examination, not a single document issued before the 9th month of Eiroku 10 exists, and prohibition notices and confirmation grants are concentrated in the 9th and 10th months of Eiroku 10. Moreover, the imperial decree of Emperor Ōgimachi dated the 9th day of the 11th month of Eiroku 10, ordering Nobunaga to restore an imperial estate presumed to be within Mino Province (the “Tachiiri Monjo”), serves as decisive corroborating evidence.

The “History of Gifu City” too concludes that “there is no room whatsoever for doubt that the fall of Inabayama Castle by Nobunaga was in Eiroku 10, and the Eiroku 7 theory is hard to support from the standpoint of the research methods of present-day historiography.”

Why was the Edo-period received view born?

Then why did Edo-period war chronicles adopt Eiroku 7? It is highly likely that the seizure of Inabayama Castle by Takenaka Hanbee in Eiroku 7 (1564) and Nobunaga’s capture of Inabayama Castle in Eiroku 10 (1567) were confused in the course of oral transmission. Both were incidents in which “Inabayama Castle fell,” and although there was a three-year gap, later compilers came to treat them as one and the same.

It is a good example of how a historical “received view” changes from age to age. It can be called a typical case in which a received view continuing from the Edo period was overturned by the methods of modern historiography, which rigorously examines primary sources.

Theory 2: Was Inabayama Castle Really “Impregnable”?

Inabayama Castle has been praised as “an impregnable fortress.” It was a mountain castle built atop Mt. Kinka, about 330 meters in elevation, a natural stronghold of steep terrain and bedrock. In Shiba Ryōtarō’s novels and in historical manga, too, it has been depicted as an impregnable castle that Nobunaga struggled against for many years.

It is true that Nobunaga could not directly storm Inabayama Castle. After the Battle of Moribe in Eiroku 4, riding the momentum he attacked Inabayama Castle but withdrew without capturing it. At the Battle of Shinkanō in Eiroku 6, he was defeated by Takenaka Hanbee’s ambush tactics. The Kagamino deployment of Eiroku 9 also ended in retreat owing to the difficulty of the terrain.

However, recent research holds that the direct cause of Inabayama Castle’s fall was not “the sturdiness of the castle itself” but “the collapse of the political system that sustained the castle.”

The true reasons Inabayama Castle fell

• The defection of the West Mino Triumvirate left the castle completely isolated.
• The burning of the castle town of Inokuchi cut off its supplies.
• The defection of the retainer band collapsed the morale of the defending troops.
• After a two-week siege, Tatsuoki surrendered (it was not a fall by force of arms).

In other words, Inabayama Castle was indeed “an impregnable castle that could not be taken by force,” but it “collapsed from the inside” through political power and stratagem. That Nobunaga “captured” Inabayama Castle is a fact, but it was not a forceful siege assault—it was a victory of skillful political warfare.

This shows that Nobunaga’s true ability lay not in “strength in combat” but in “a comprehensive strategy combining politics, economics, and information.” The essence of Nobunaga’s string of victories, continuing up to the Honnō-ji Incident, was already apparent in the Battle of Inabayama Castle.

Theory 3: The True Motive Behind Takenaka Hanbee’s Seizure of Inabayama Castle

The seizure of Inabayama Castle by Takenaka Hanbee in the 2nd month of 1564 (Eiroku 7) is one of the most famous anecdotes in Sengoku history. “A loyal retainer who, to admonish the folly of his lord Tatsuoki, took the castle with only sixteen men and selflessly returned it half a year later”—this is the traditional interpretation.

But recent research has greatly rewritten this fine tale.

The traditional “admonishing the lord” theory

The framing in which Hanbee, indignant that his lord Tatsuoki was indifferent to government and favored only a portion of his retainers, seized the castle to prompt Tatsuoki’s self-reflection. The “surprise attack with sixteen men” and the “selfless return of the castle” are emphasized as a fine tale.

The recent “coup” theory

Through the research of historians, several noteworthy facts have come to light:

• It was not Hanbee acting alone; about 2,000 troops of his father-in-law Andō Morinari (one of the West Mino Triumvirate) were mobilized.
• The “surprise attack with sixteen men” is an embellishment of Edo-period war chronicles such as the “Hōan Shinchō-ki.”
• For half a year after the takeover, Hanbee and Morinari sent documents to the various commanders around them, busily working to gather support.
• It is highly likely they were aiming for a full-scale change of government with the backing of Mino’s various commanders.
• Rather than “returning the castle,” it is also possible that Tatsuoki gathered troops and retook it.
• Hanbee’s subsequent withdrawal into seclusion may have been not a “selfless departure” but an avoidance of punishment as the ringleader of a coup.

In other words, the current leading view is that Hanbee’s action was highly likely not “the admonition of a loyal retainer” but a full-scale coup by the anti-Tatsuoki faction.

The theory of Nobunaga’s involvement

More intriguing still is the connection with Nobunaga. It is said that immediately after the takeover, Nobunaga tempted Hanbee with the offer “If you hand over Inabayama Castle, I will grant you half of Mino Province.” There is also a tradition that the envoy who conveyed this offer was Hideyoshi. If this were true, the possibility arises that Hanbee’s takeover was a stratagem coordinated with Nobunaga.

The full picture of the coup and its relationship to Nobunaga have not been completely clarified, owing to the limits of the sources. But it is certain that this incident, long told as a “simple fine tale,” was a typical case of the power struggles of the Sengoku period. The true protagonist of this incident was probably not “Hanbee’s loyalty” but “the fragility of the Tatsuoki regime.”

Theory 4: Did Nobunaga Really Fail at the Conquest of Mino Again and Again?

The capture of Inabayama Castle is said to be “a long-cherished goal that Nobunaga achieved over seven years.” It is true that from just after Okehazama in 1560 (Eiroku 3) to the fall of the castle in 1567 (Eiroku 10), seven years passed. But it is not fair to evaluate all of Nobunaga’s actions in that interval as “failures.”

Grounds for the failure theory

• Repelled by Nagai Toshifusa in the invasions of the 6th and 8th months of Eiroku 3.
• Withdrew from the attack on Inabayama Castle in Eiroku 4.
• Defeated by Takenaka Hanbee at the Battle of Shinkanō in Eiroku 6.
• Defeated by Tatsuoki at the Battle of Kōnoshima in Eiroku 9.
• Could not directly storm Inabayama Castle.

The strategic-progress theory

On the other hand, over the seven years Nobunaga was steadily accumulating results:

• Won the Battle of Moribe and the Battle of Jūshijō in Eiroku 4.
• Around Eiroku 7, moved his base from Kiyosu Castle to Komakiyama Castle, turning it into a forward base for the conquest of Mino.
• In the Naka-Mino campaign of Eiroku 8, took Kajita Castle and Dōhora Castle, subduing the Naka-Mino region.
• Absorbed the Mino kokujin one after another, eroding the Saitō clan’s base of support.
• Incorporated men of Mino origin, such as Mori Yoshinari and Kawajiri Hidetaka, into his retainer band.

In other words, Nobunaga’s conquest of Mino was not “a series of failures in decisive battles” but “a strategy of avoiding decisive battle, drawing the enemy into a long war of attrition, and gradually eroding the Saitō clan’s base of support.” It was Nobunaga’s true method to win not by the outcome of short-term battles but by a comprehensive political and economic strategy.

Seen from this viewpoint, the defection of the West Mino Triumvirate in Eiroku 10 should be assessed not as “chance good fortune” but as “the fruit of seven years of strategic effort.” Nobunaga won over the kokujin of Mino one by one and collapsed the Saitō clan from within.

The same method was repeated in Nobunaga’s other campaigns of conquest. The ten-year war with the Honganji, the confrontation with the Takeda house, the attack on the Mōri—all were victories of “comprehensive strategy” rather than “decisive battle.” Nobunaga’s essence lay in being a “comprehensive strategist” who combined the foremost economic power, intelligence power, and stratagem of the Sengoku period. The Battle of Inabayama Castle was the first great success of that method.

Theory 5: Was the Defection of the West Mino Triumvirate the Fruit of Nobunaga’s Stratagem, or a Natural Defection?

Regarding the defection of the West Mino Triumvirate (Inaba Yoshimichi, Ujiie Bokuzen, and Andō Morinari) that became the decisive factor in Inabayama Castle’s fall, there are several theories about its motive and circumstances.

The theory of Nobunaga’s successful stratagem

The view that Nobunaga spent years working a stratagem upon the Triumvirate, at last bringing it to fruition in the form of the offering of hostages. In fact, there is a possibility that Nobunaga had already had some contact with Andō Morinari after the Hanbee incident of Eiroku 7. Moreover, Nobunaga was winning over the Mino kokujin one after another, and the Triumvirate can be explained as part of the same current.

The natural-defection theory

The view that the Triumvirate, treated coldly within the Tatsuoki regime, voluntarily submitted to Nobunaga for the survival of their own houses. Tatsuoki was young and indifferent to government, doting on a portion of his retainers (such as Saitō Hida-no-kami) and keeping his powerful chief retainers at a distance. Though the Triumvirate had jointly signed as among the four chief retainers of the Saitō house at the Battle of Kōnoshima, it is conjectured that they grew discontented with their subsequent treatment.

The composite theory (the recent mainstream)

It is reasonable to think it was the result of Nobunaga’s stratagem and the Triumvirate’s own voluntary judgment acting together compositely. Over the seven-year course of the conquest of Mino, Nobunaga had steadily expanded his network of personal connections among the Mino kokujin. Meanwhile, the corruption and incompetence of the Tatsuoki regime naturally inclined the Triumvirate toward Nobunaga’s side. In the 8th month of Eiroku 10, when the interests of both coincided, it came to fruition in the form of defection.

What deserves attention is that, after the Triumvirate defected, Nobunaga did not execute them or confiscate their territories but continued to treat them as senior retainers. Inaba Yoshimichi later became known as “Inaba Ittetsu,” whose stubborn character became the origin of the expression “ganko ittetsu” (stubborn to the core), and Ujiie Bokuzen was active as a retainer of Nobunaga. Only Andō Morinari was later expelled in 1580 (Tenshō 8) on suspicion of secret communication with Takeda Shingen, but this was a separate matter from the Inabayama defection.

The true mark of Nobunaga’s stratagem lay not only in “making the enemy switch sides” but also in “how he treated them after they switched.” Precisely because he treated the Triumvirate generously, other Sengoku daimyō could trust that “surrendering to Nobunaga would not bring bad treatment,” and his subsequent campaigns proceeded smoothly.

Theory 6: Was Saitō Tatsuoki Really a “Foolish Lord”?

Ever since the Edo-period war chronicles, Saitō Tatsuoki has been appraised as “a foolish lord indifferent to government” and “a dull-witted ruler who indulged in drink and women and kept able retainers at a distance.” Takenaka Hanbee’s takeover incident and the West Mino Triumvirate’s defection have all been attributed to Tatsuoki’s folly.

But recent research has cast doubt on this received view.

Tatsuoki’s achievements

Tatsuoki succeeded to the headship at fourteen—extremely young for a Sengoku daimyō. Yet over the seven years of war with Nobunaga, Tatsuoki won several important victories:

• Defeated Nobunaga’s army at the Battle of Shinkanō in 1563 (Eiroku 6).
• Defeated Nobunaga at the Battle of Kōnoshima in 1566 (Eiroku 9) (the Saitō clan’s last victory).
• Recovered Mino from the coup of Takenaka Hanbee and Andō Morinari in Eiroku 7.

These achievements contradict the image of Tatsuoki as “a fool indifferent to government.” At the very least, he possessed enough military and political power to repel Nobunaga directly.

The origin of the “foolish lord” image

Then why did the image of a “foolish lord” become fixed? Several factors have been pointed out:

• Hindsight: because he was the loser who ultimately lost Mino, later evaluations are harsh.
• Edo-period storytelling: to set off the heroic legend of Nobunaga, portrayals denigrating Tatsuoki increased.
• Linkage with the Hanbee fine tale: for the framing of “the loyal retainer Hanbee admonishing a foolish lord,” it was necessary to depict Tatsuoki as foolish.
• Youth: he succeeded at fourteen and died at the end at a young twenty, so his immaturity stood out.

Of course, Tatsuoki had clear failures too. That he doted on a portion of his retainers (such as Saitō Hida-no-kami) and treated the West Mino Triumvirate coldly was a decisive failure that invited division within the house. There were likely also the naivety of political judgment that came with youth, and the mental weakness that could not endure the long war with Nobunaga.

But it is not fair to appraise Tatsuoki one-sidedly as “a foolish loser.” He should be seen as “a tragic young Sengoku daimyō who lost the Mino his father and grandfather had built, at only twenty.” Ironically, after losing Mino, Tatsuoki fought on against Nobunaga, moving from place to place, and died in battle at the Battle of Tonezaka in 1573 (Tenshō 1). His figure, fighting to the very end, shows a Sengoku warrior’s spirit different from the image of “folly.”

Viewed Strategically

What deserves attention in the Battle of Inabayama Castle is the completed form of Nobunaga’s “comprehensive strategy.”

First, the strategic nature of the long war of attrition. Nobunaga spent seven years on the conquest of Mino. Rather than rushing for a short-term victory, he eroded the Saitō clan’s base of support little by little, year by year. He won local victories at the Battles of Moribe and Jūshijō, absorbed the Naka-Mino kokujin in the Naka-Mino campaign, and moved his base from Kiyosu to Komakiyama to build a forward base. Each of these was a small result, but accumulated, they collapsed the Saitō clan of Mino from the inside. Nobunaga’s method—not seeking “decisive battle” but winning through “comprehensive strategy”—was completed at the Battle of Inabayama Castle.

Second, the use of stratagem and political marriage. The starting point of Nobunaga’s conquest of Mino was the political marriage to Kichō (Nōhime) that accompanied the reconciliation in his father Nobuhide’s time. The alliance with Dōsan, the Shōtoku-ji meeting, and Dōsan’s testament—all of these became Nobunaga’s “justification” for the conquest of Mino. The claim “I am the legitimate successor who carries on Dōsan’s will” gave the Mino kokujin a psychological basis: “submission to Nobunaga is not betrayal but the restoration of legitimacy.” Nobunaga’s strategy of mobilizing not only military force but even political legitimacy was among the foremost of the Sengoku period.

Third, the use of economic power. Nobunaga controlled the economic centers of Tsushima and Atsuta in Owari, and with that wealth he could maintain the separation of soldier from farmer and a standing army. Unlike other Sengoku daimyō who depended on rice tax, Nobunaga obtained funds through trade and through taxes on toll barriers and guilds. This secured the fiscal power to sustain a long war lasting seven years. Meanwhile, the young Tatsuoki could not secure new sources of income and squandered his war funds. The gap in economic power ultimately appeared as a gap in strategy.

Fourth, the skill of his treatment of the enemy. After making the West Mino Triumvirate defect, Nobunaga did not execute them or confiscate their territories but continued to treat them generously as senior retainers. This bred the trust that “surrendering to Nobunaga would not bring bad treatment,” and his subsequent campaigns proceeded smoothly. This skill in “treatment after switching sides” became one of Nobunaga’s greatest weapons as a later Sengoku daimyō.

That said, Nobunaga had his limits too. In direct battles he suffered defeat again and again. He lost to Takenaka Hanbee at Shinkanō and to Tatsuoki at Kōnoshima. Nobunaga’s true strength lay not in “strength in individual combat” but in “comprehensive strategy beyond combat.” This is also a structural weakness that connects to his later failure at the Honnō-ji Incident of “not seeing through a retainer’s treachery.”

The Battle of Inabayama Castle was the starting point of Nobunaga’s enterprise of unifying the realm and, at the same time, the completed form of his method. To collapse a formidable enemy from the inside through a comprehensive strategy combining economics, information, stratagem, and political legitimacy—this method of Nobunaga’s would be used repeatedly after Inabayama in the confrontations with the Honganji, the Takeda, and the Mōri.

Right after the battle, Nobunaga began to use the “Tenka Fubu” seal, and the next year he marched on the capital bearing Ashikaga Yoshiaki. That he had gained the geographic and economic base of Mino decisively changed the balance of power of the Sengoku period. The Battle of Inabayama Castle was not merely one engagement but an important turning point marking the first step toward the end of the Sengoku era.

Famous Words and Sayings of This Battle

“Tenka Fubu”

The characters on the seal that Nobunaga began to use from around the 11th month of 1567 (Eiroku 10), after the conquest of Mino. Long taken to mean “to unify the realm by force of arms,” in recent research the interpretation “to extend the shogunate’s authority throughout the Kinai” or “a statement of resolve in the manner of a personal motto” has gained ground. In any case, it is engraved in Sengoku history as the four characters symbolizing Nobunaga’s vision of the realm. The choice of the words is said to have been made by Takugen Sōon, abbot of Seishū-ji, the temple memorializing Nobunaga’s tutor Hirate Masahide.

— Source: “Seishū-ji Records” and others

“Gifu”

The place name to which Nobunaga renamed the castle town of Inokuchi after the conquest of Mino. It is said to derive from Mt. Qi (Kizan), where the ancient Chinese Zhou dynasty unified the realm. Takugen Sōon proposed the naming to Nobunaga. The “Gi” points to the lore of the Zhou dynasty, and the “fu” points to Qufu, the birthplace of Confucius—imbued with the meaning of a land combining both the martial and the civil. The renaming of the place was a symbolic act showing that Nobunaga was conscious not of mere territorial acquisition but of “taking the realm.”

— Source: “Seishū-ji Records”

“We are coming over to your side, so please receive our hostages.”

Said to be the words with which the West Mino Triumvirate (Inaba Yoshimichi, Ujiie Bokuzen, and Andō Morinari) proposed their defection to Nobunaga on the 1st day of the 8th month of 1567 (Eiroku 10). For three powerful chief retainers of the Saitō house to submit to Nobunaga together was extremely exceptional even for the Sengoku period. This single utterance became the decisive blow that completed Nobunaga’s long conquest of Mino.

— Source: Ōta Gyūichi, “Shinchō Kōki”

“Is this friend or foe?”

Said to be the words uttered in bewilderment by a retainer of Tatsuoki’s side when Nobunaga came running up Zuiryūji-yama. Because the defection of the West Mino Triumvirate caused Nobunaga to appear suddenly in the heart of Mino, those within the castle could not grasp what was happening. In the gap of this confusion, Nobunaga burned down the castle town of Inokuchi and reduced Inabayama Castle to a naked castle. It is a scene symbolizing Nobunaga’s superiority in information warfare.

— Source: Ōta Gyūichi, “Shinchō Kōki,” “On the Taking of Inabayama”

Anecdotes and Episodes

Dōsan’s Testament — Nobunaga’s Justification

Just before the Battle of Nagaragawa in 1556 (Kōji 2), Saitō Dōsan wrote a testament addressed to Nobunaga ceding Mino Province to him. The original is lost, but three copies survive. They are kept at Myōkaku-ji in Kyoto and at the Osaka Castle keep, and the testament is also recorded in the “Kōnōki.”

Nobunaga made maximum use of this testament as his justification for the conquest of Mino. The claim “I am the legitimate successor who inherits Mino in accordance with the testament of my father-in-law Dōsan” carried strong persuasive force with the Mino kokujin. The rule of Yoshitatsu and Tatsuoki was positioned as “usurpation,” and submission to Nobunaga was justified not as “betrayal” but as “the restoration of legitimacy.”

That after the fall of Inabayama Castle Nobunaga renamed it “Gifu” and raised the banner of “Tenka Fubu” was also part of the narrative of taking the realm as the heir to Dōsan’s will. The “prophecy” since the Shōtoku-ji meeting, at which Dōsan had seen through Nobunaga, came to fruition here.

— Source: “Kōnōki” and various studies

Did Takenaka Hanbee Really Take Inabayama Castle With Only Sixteen Men?

In the 2nd month of 1564 (Eiroku 7), Takenaka Hanbee, together with his father-in-law Andō Morinari, made a sudden assault on and seized Inabayama Castle, the stronghold of his lord Saitō Tatsuoki. In Edo-period war chronicles it has been told as the dramatic tale that “Hanbee took over the castle with only sixteen men.”

The story handed down in the “Hōan Shinchō-ki” runs thus. Hanbee had offered his younger brother Kyūsaku Shigenori as a hostage at Inabayama Castle. One day, receiving a false report that his brother was ill, Hanbee went up to the castle to visit him. Hiding weapons in a box meant for medical implements, he entered the castle and seized it with a small band of men.

But recent research has shown that this story is greatly embellished. In reality it was a coup in which about 2,000 troops of Andō Morinari were mobilized, and “sixteen men” was an exaggeration. It has also been pointed out that, rather than “returning the castle half a year later,” Tatsuoki may have gathered troops and retaken it.

This incident, passed down as a dramatic fine tale, was in fact highly likely a full-scale coup by the anti-Tatsuoki faction. A “fine tale” rewritten as a “power struggle”—it is a typical case in which the advance of historiography brought a new interpretation.

— Source: “Hōan Shinchō-ki,” recent research

→ For details, see the warlord article “Takenaka Hanbee.”

The Sunomata One-Night Castle — Was It Actually a Legend?

Speaking of Nobunaga’s conquest of Mino, the episode of the “Sunomata One-Night Castle” is famous. The story goes that in 1566 (Eiroku 9), Toyotomi Hideyoshi, then still calling himself Kinoshita Tōkichirō, built a castle at Sunomata along the Nagara River in a single night and impressed Nobunaga.

This anecdote has been widely known from the Edo period to the present as an episode symbolizing Hideyoshi’s quick wit and ability. But recent research holds that this story is not historical fact but an Edo-period invention. It does not appear in the primary source “Shinchō Kōki,” and the “Kawanami-shū,” the group said to have supported Hideyoshi, is also thought to be a later invention.

That said, it is probably a fact that Nobunaga did try to build a forward base in the course of the conquest of Mino. The area around Sunomata was located on the border of Mino and Owari and was a strategically important point. To what degree Hideyoshi actually played a role is unknown, but his involvement in the conquest of Mino in his youth was a foreshadowing of his later rise.

— Source: various works, recent research

The Burning of Inokuchi on a Day of Strong Wind

On the 1st day of the 8th month of 1567 (Eiroku 10), Nobunaga ran up Zuiryūji-yama and secured a position commanding a view of the castle town of Inokuchi. And he set it ablaze. The “Shinchō Kōki” records that “that day was exceptionally windy.”

The flames, riding the strong wind, covered the town in an instant, and Inokuchi was reduced to ashes. Having lost its castle town, Inabayama Castle was robbed of the limbs of supply and defense and became a “naked castle.” The chance of the strong wind of the 8th month sided with Nobunaga.

At the Battle of Okehazama too, Nobunaga surprise-attacked Yoshimoto’s headquarters under cover of a downpour. That the weather worked in Nobunaga’s favor at important battles was not mere chance. Nobunaga’s “prepared fortune”—observing geography and weather daily and moving when he saw his chance—was displayed at the Battle of Inabayama Castle as well.

— Source: Ōta Gyūichi, “Shinchō Kōki,” “On the Taking of Inabayama”

The Lore of the Naming of “Gifu”

Having gained Inabayama Castle, Nobunaga immediately changed the names of the castle and the castle town. “Inabayama Castle” was renamed “Gifu Castle,” and “Inokuchi” was renamed “Gifu.” The one who proposed the naming is said to be Takugen Sōon, abbot of Seishū-ji, the temple memorializing Nobunaga’s tutor Hirate Masahide.

Deep meaning is imbued in the place name “Gifu.” The “Gi” derives from Mt. Qi, where the ancient Chinese Zhou dynasty unified the realm, and the “fu” points to Qufu, the birthplace of Confucius. A land combining both the martial and the civil—this was the ambition Nobunaga imbued in the new place name.

At the same time, the “Tenka Fubu” seal began to be used. Takugen Sōon is said to have chosen the words “Tenka Fubu” as well. Both the place name and the seal inscription became symbols showing Nobunaga’s will toward unifying the realm. The victory of a single battle was inscribed, through the changes of place name and seal, as the first step toward the end of the Sengoku era.

— Source: “Seishū-ji Records,” various studies

Tatsuoki’s Later Life — He Fought Nobunaga to the Very End

Having lost Inabayama Castle, Saitō Tatsuoki fled along the Nagara River to Nagashima in northern Ise. He was twenty at the time. In the received view from the Edo period onward he was depicted as “a foolish lord drowned in drink and women,” but in reality Tatsuoki never gave up his resistance to Nobunaga to the very end.

At Nagashima he allied with the Ikkō-ikki and fought Nobunaga’s army. At the Battle of Noda-Fukushima in the 8th month of 1570 (Genki 1), together with Miyoshi Yasunaga, Atagi Nobuyasu, and others, he supported the defense of the Miyoshi Triumvirate, achieving results enough to make Nobunaga retreat. Thereafter he relied on Asakura Yoshikage of Echizen and continued his resistance to Nobunaga.

In the 8th month of 1573 (Tenshō 1), at the Battle of Tonezaka, where the Asakura clan was attacked by Nobunaga, Tatsuoki died in battle as a member of the Asakura army. He was 26 (there are other theories). Like his father Yoshitatsu, who died of illness at 35, and his grandfather Dōsan, who was killed at Nagaragawa, he was fated to fall on the battlefield in his twenties.

Contrary to the image of “a foolish loser,” Tatsuoki showed the spirit of a Sengoku warrior to the very end. The bloodline of the Saitō clan of Mino died out with Tatsuoki’s death. The roughly 100-year history of the Saitō clan of Mino, counting from his father Dōsan and grandfather Nagai Shinzaemon-no-jō, closed its curtain amid the turmoil of the Sengoku era.

— Source: “Shinchō Kōki,” various studies

Battle of Inabayama Castle Timeline

Period	Event
Kōji 2 (1556)	Dōsan dies at the Battle of Nagaragawa. The testament ceding Mino Province to Nobunaga is written.
5th month, Eiroku 3 (1560)	Nobunaga defeats Imagawa Yoshimoto at the Battle of Okehazama. Toward the full-scale conquest of Mino.
6th & 8th months, Eiroku 3	Nobunaga invades Mino but is repelled by Nagai Toshifusa and others.
5th month, Eiroku 4 (1561)	Yoshitatsu dies of illness at 35; the fourteen-year-old Tatsuoki succeeds. Nobunaga wins the Battles of Moribe and Jūshijō.
Eiroku 5 (1562)	Nobunaga concludes the Kiyosu Alliance with Tokugawa Ieyasu.
Eiroku 6 (1563)	Nobunaga is heavily defeated by Takenaka Hanbee at the Battle of Shinkanō. The attack on eastern Naka-Mino fails.
2nd month, Eiroku 7 (1564)	Takenaka Hanbee and Andō Morinari make a sudden assault on and seize Inabayama Castle (half a year later it is returned to or retaken by Tatsuoki).
Eiroku 8 (1565)	The Naka-Mino campaign. Satō Tadayoshi, lord of Kajita Castle, defects to Nobunaga, and Naka-Mino enters Nobunaga’s sphere.
4th month, Eiroku 9 (1566)	Nobunaga deploys as far as Kagamino but retreats.
Intercalary 8th month, Eiroku 9	Tatsuoki defeats Nobunaga at the Battle of Kōnoshima (the Saitō clan’s last victory).
1st day, 8th month, Eiroku 10 (1567)	The West Mino Triumvirate (Inaba Yoshimichi, Ujiie Bokuzen, Andō Morinari) propose defection to Nobunaga. Nobunaga advances at once and takes Zuiryūji-yama.
1st day, 8th month, Eiroku 10	Amid a strong wind, Nobunaga burns down the castle town of Inokuchi. Inabayama Castle becomes a naked castle.
14th day, 8th month, Eiroku 10	Nobunaga builds a shishigaki palisade around Inabayama Castle, completely encircling it.
15th day, 8th month, Eiroku 10 (other theory: 15th of 9th month)	Tatsuoki surrenders and opens the castle. He flees to Nagashima in northern Ise.
Latter half of Eiroku 10 (1567)	Nobunaga renames Inabayama Castle “Gifu Castle” and Inokuchi “Gifu.” Begins using the “Tenka Fubu” seal.
9th month, Eiroku 11 (1568)	Nobunaga marches on the capital bearing Ashikaga Yoshiaki and installs him as the fifteenth shogun.
Tenshō 1 (1573)	Tatsuoki dies in battle at the Battle of Tonezaka. The Saitō clan of Mino perishes.

* Dates are in the old (lunar) calendar. Row shading: yellow = the decisive-battle period; red = Nobunaga’s defeats.

Battle of Inabayama Castle: Key Figures of Both Armies

The Oda Army

Role	Person	Summary
Supreme commander	Oda Nobunaga	Age 33. Completed the seven-year conquest of Mino. After the battle raised the banner of “Tenka Fubu.”
Hostage receiver	Murai Sadakatsu	A Nobunaga retainer dispatched to receive the Triumvirate’s hostages.
Hostage receiver	Shimada Hidemitsu	A Nobunaga retainer dispatched to receive the Triumvirate’s hostages.
Retainer	Mori Yoshinari	A Nobunaga retainer of Mino origin; granted Kanayama Castle in the Naka-Mino campaign.
Retainer	Kawajiri Hidetaka	A Nobunaga retainer of Mino origin; granted Sarubami Castle.
Retainer (tradition)	Kinoshita Tōkichirō (later Toyotomi Hideyoshi)	The Sunomata one-night castle tradition (its historicity is doubtful).
Defector	Inaba Yoshimichi (Ittetsu)	Head of the West Mino Triumvirate. After defecting, active as a senior retainer of Nobunaga.
Defector	Ujiie Bokuzen (Naomoto)	One of the West Mino Triumvirate, a chief retainer of Tatsuoki.
Defector	Andō Morinari (Dōsoku)	One of the West Mino Triumvirate, Hanbee’s father-in-law. Ringleader of the 1564 coup.

The Saitō Army

Role	Person	Summary
Supreme commander	Saitō Tatsuoki	Age 20. Third-generation lord of the Saitō clan of Mino. Lost the castle and fled to Nagashima.
Retainer	Saitō Hida-no-kami	One of the retainers favored by Tatsuoki. A figure disliked by Hanbee.
Chief retainers (later defected)	Andō Morinari and Ujiie Bokuzen	Among the four chief retainers who jointly signed at Kōnoshima in Eiroku 9; defected to Nobunaga in Eiroku 10.
Retainer (defected)	Takenaka Hanbee	After the Eiroku 7 seizure of Inabayama Castle, withdrew into seclusion. Later became Hideyoshi’s strategist.
Dōsan’s surviving retainer	Saitō Toshiharu	Dōsan’s youngest son. Later became a retainer of Nobunaga.

Related Historic Site Map / Travel Model Course

Related Historic Site Map — Battle of Inabayama Castle

Spots on the Map:

• Gifu Castle (former Inabayama Castle) (castle) — The stage of the battle, the main castle of Mino that Nobunaga gained.
• Zuiryūji-yama (mountain) — The mountain Nobunaga ran up to begin his attack.
• Gifu Park (site of Inokuchi) (old battlefield) — The castle town burned by Nobunaga.
• Nagara River (terrain) — The geographic center of the battlefield.
• Jōzai-ji (family temple) — The Saitō clan’s family temple, a place forming the background of the battle.
• Komakiyama Castle (castle) — The castle Nobunaga used as a forward base for the conquest of Mino.
• Shinkanō old battlefield (old battlefield) — The place where Hanbee defeated Nobunaga.
• Moribe old battlefield (old battlefield) — The place where Nobunaga won in Eiroku 4.
• Sunomata One-Night Castle ruins (legendary castle) — The place of the Hideyoshi tradition (its historicity is doubtful).

* The map is a reference display based on modern roads. It differs from the roads and terrain of the Sengoku period.

Travel Model Course — A One-Day Course Tracing Nobunaga’s Conquest of Mino

Preconditions

• Required time: about 5–6 hours (by car).
• Centered on the city of Gifu, touring the main spots of the battle.

Model Course

① Komakiyama Castle (stay: about 60 min)
The castle Nobunaga built as a forward base for the conquest of Mino. From here one can command a view toward Inabayama Castle.
– By car: about 10 min from the Komaki IC of the Meishin Expressway, coming from the Nagoya direction.

② Gifu Park / site of Inokuchi (stay: about 40 min)
The castle town burned by Nobunaga. Today it is maintained as a park.
– By car: about 40 min from Komakiyama Castle.

③ Gifu Castle (former Inabayama Castle) (stay: about 120 min)
The summit of Mt. Kinka, 330 m in elevation. One can ascend to the summit station by ropeway. From the keep one commands a view of the Nagara River and the city of Gifu, experiencing the scenery Nobunaga saw.
– Ropeway from Gifu Park.

④ Jōzai-ji (stay: about 60 min)
The Saitō clan’s family temple. It holds the graves of three generations—Dōsan, Yoshitatsu, and Tatsuoki. One can understand the history of the Saitō clan that forms the background of the battle.
– By car: about 15 min from Gifu Park.

⑤ Zuiryūji-yama (stay: about 40 min)
The mountain Nobunaga ran up to begin his attack. It can still be climbed today as a hiking course.
– By car: about 20 min from Jōzai-ji.

Arrangements by Type of Traveler

• For the strong of leg: Add the Shinkanō old battlefield (where Hanbee defeated Nobunaga) and the Sunomata One-Night Castle ruins.
• For the leisurely: Shorten to a half-day course of Gifu Castle plus Gifu Park.
• For history enthusiasts: Add the Moribe old battlefield (Nobunaga’s victory site of Eiroku 4) and the Kōnoshima old battlefield (Nobunaga’s defeat site of Eiroku 9) to fully trace the seven-year war between Nobunaga and the Saitō clan.

* This plan is a reference model based on general travel speeds and stay times. Facility hours, transit schedules, and crowd conditions vary by season and day of the week. When going out, please check the latest information on the official websites of each facility and transit operator.

* Mountain-entry and admission fees are reference prices as of the time of writing. They may have changed.

* For climbing to mountain castle ruins, please make a reasonable plan according to weather and your physical condition.

Related Articles

Battle Articles

• Battle of Okehazama (1560) — The starting point of Nobunaga’s conquest of Mino.
• Battle of Anegawa (1570) — Nobunaga’s enterprise of unifying the realm after the conquest of Mino.
• The Honnō-ji Incident (1582) — Nobunaga’s end.

Warlord Articles

• Oda Nobunaga — The protagonist of the battle, who gained Mino and raised the banner of “Tenka Fubu.”
• Saitō Dōsan — Nobunaga’s father-in-law, author of the testament ceding Mino Province.
• Saitō Yoshitatsu — Tatsuoki’s father, the able man who repelled Nobunaga.
• Takenaka Hanbee — Defeated Nobunaga at the Battle of Shinkanō; protagonist of the Inabayama Castle takeover incident.
• Mori Yoshinari — A man of merit in Nobunaga’s conquest of Mino.
• Toyotomi Hideyoshi — The Sunomata one-night castle tradition.
• Ashikaga Yoshiaki — The shogun installed by Nobunaga right after the battle.

References

Primary Sources

• Ōta Gyūichi, “Shinchō Kōki” — “On the Taking of Inabayama,” the most important source.
• “Nakajima Monjo” — the jointly signed victory report from Kōnoshima dated the 18th day of the intercalary 8th month of Eiroku 9 (decisive grounds for the Eiroku 10 theory).
• “Tachiiri Monjo” — the imperial decree of Emperor Ōgimachi dated the 9th day of the 11th month of Eiroku 10.
• “Zuiryūji Shie Rinban Sedaichō” — records “the intrusion of Oda Kazusa in the 9th month of Eiroku 10.”
• “Rekidai Koan, vol. 1” — Nobunaga’s letter to Naoe Kagetsuna dated the 9th day of the 9th month of Eiroku 7.
• Copy of a letter by Kaisen Jōki, “Shōgonkō Records” — records the Inabayama Castle takeover incident of Takenaka Hanbee.

Academic Works

• Taniguchi Katsuhiro, “Nobunaga’s Road to Tenka Fubu” (Yoshikawa Kōbunkan, 2006).
• Yokoyama Sumio, “Saitō Dōsan and Yoshitatsu and Tatsuoki: The Local Order of Sengoku Mino” (Ebisu Kōshō Shuppan, 2015).
• Kinoshita Satoshi, “Four Generations of the Saitō Clan” (Minerva Shobō, 2020).
• Watanabe Daimon, ed., “A Combat History of Nobunaga’s Army, 1560–1582” (Yoshikawa Kōbunkan, 2016).
• Katsumata Shizuo, “History of Gifu” — additional verification of the Eiroku 10 theory.
• “History of Gifu City” — a synthesis of modern research.

Historiography from the Meiji Era Onward (Establishing the Eiroku 10 Theory)

• Kuroita Katsumi, “Studies in National History” (1908).
• Watanabe Yosuke, “History of the Azuchi Period” (1910).
• Toki Kinsen, “Draft Gazetteer of Mino” (1915).
• Abe Einosuke, “Comprehensive History of the Two Provinces of Mino and Hida” (1925).

Public Materials

• Gifu Castle Museum.
• Gifu City Museum of History.
• “Gifu Castle” official tourism guide.

* This article is composed on the basis of the sources, research works, and papers above, as well as multiple information sources on the web. There are points on which interpretations of history differ even among researchers, and established views may change with the discovery of new sources or the advance of research.