Ieyasu's Iga Flight

The Shinkun Iga-goe (Ieyasu's flight through Iga) refers to the event in which Tokugawa Ieyasu escaped from Sakai to Okazaki Castle in Mikawa Province by way of Iga and Kōka, immediately after the Honnōji Incident of the 2nd day of the 6th month of Tenshō 10 (1582). "Shinkun" (Divine Lord) is an honorific that later generations used for Ieyasu after he had been deified, and this flight came to be passed down as a mythic tale of the Tokugawa house. It is an important historical episode showing how Ieyasu, amid the greatest shock of the Sengoku period, the Honnōji Incident, overcame a mortal crisis and laid the groundwork for the later unification of the realm.

Background: The Honnōji Incident and Ieyasu's Position

On the morning of the 2nd day of the 6th month of Tenshō 10, the forces of Akechi Mitsuhide attacked Honnō-ji in Kyoto, and Oda Nobunaga died. At that time, Tokugawa Ieyasu was on a sightseeing journey from Azuchi Castle to Sakai (present-day Sakai, Ōsaka Prefecture) at the invitation of his ally Nobunaga. His retinue numbered only about 34 people (the party of Anayama Nobukimi (Baisetsu) also accompanied him), and he did not lead a large army.

News of Nobunaga's death is said to have reached Ieyasu's party, which was traveling from Sakai toward Kyoto, near Mount Iimori in Kawachi Province, on the same day. Ieyasu's situation was extremely perilous. If Mitsuhide's forces seized the Tōkaidō, the route back to Mikawa would be cut off. Chaya Shirōjirō Kiyonobu, a wealthy merchant of Kyoto, is said to have brought word of the emergency and supported the escape both materially and in spirit.

Route of the Escape and Its Hardships

Ieyasu's party went from Kawachi through Ujitawara in Yamashiro, entered Kōka in Ōmi, and passed through Iga and Ise to return to Mikawa, following the route known as the "Iga-goe" (there is also a theory that they passed through Yamato). This route ran through mountainous terrain, and they had to move through areas where Akechi's forces and local landholders were roaming.

Along the way, Anayama Nobukimi (Baisetsu) is said to have taken a separate course, encountered a peasant uprising, and lost his life. This was a heavy blow to Ieyasu's party. Baisetsu was a former retainer of the Takeda clan who had secretly switched allegiance to Ieyasu during the Takeda campaign of Tenshō 10 and was a meritorious man. Ironically, he lost his life in this flight.

In the Iga-goe, local landholders of Kōka and Iga are said to have played an important role in guiding and guarding the party. The names of Taraō Mitsutoshi (a local landholder of Kōka) and Hattori Hanzō Masanari (a retainer of the Tokugawa) have been handed down, and the Hattori family continued to serve the Tokugawa house even after Ieyasu gained control of the realm.

Return to Okazaki and Preparations to Strike Back

Ieyasu's party came down out of the mountains of Iga and Kōka and is said to have returned to Mikawa by boat from Shiroko in Ise Province (present-day Suzuka, Mie Prefecture), or alternatively to have returned to Okazaki Castle by land through Owari. The escape is said to have taken about two to three days.

After returning to Okazaki Castle, Ieyasu at first considered raising an army to attack Akechi Mitsuhide as a war of vengeance for Nobunaga. However, at the Battle of Yamazaki (the 13th day of the 6th month of Tenshō 10), Hashiba Hideyoshi struck first and killed Mitsuhide. Ieyasu therefore withdrew his forces and moved to secure the former Takeda domains of Kai and Shinano (the Tenshō-Jingo War).

Ieyasu's decision at this time, not to contend with Hideyoshi but to build his strength in the east, is highly regarded in later historical assessment as showing the political essence that led to Sekigahara and then to the founding of the Edo shogunate.

The Shinkun Iga-goe and Swords

Various traditions about the swords Ieyasu carried during this flight have also been handed down. Even after becoming master of the realm, Ieyasu deeply loved swords, and Sunpu Castle housed many famous blades that he had collected over his lifetime.

The tradition that Hattori Hanzō guarded Ieyasu during the Iga-goe has been passed down as an important episode showing the bond between the Hattori family and the Tokugawa house. The name of the Hanzōmon gate of Edo Castle is said to derive from the common name "Hanzō" of Hattori Masanari and his son Masanari, who were in charge of guarding this gate.

Iga and Kōka are not famous as sword-producing regions. Nevertheless, Ieyasu's flight through the mountains of this area shows that, for a samurai, the sword was a spiritual pillar and last refuge in situations where life was at stake. The sword was said to be the soul of the samurai and was to be worn close to the body in any difficult circumstance.

Historical Significance and Influence on Later Generations

The significance that the Shinkun Iga-goe left in Japanese history goes beyond a mere record of a flight.

First, this event functioned as proof of the legitimacy of the Tokugawa house. Later Tokugawa people spoke of Ieyasu's survival, through wit and courage even in the unprecedented crisis of the Honnōji Incident, as a sign of Heaven's mandate. The name "Shinkun Iga-goe" also arose in the Edo period, when Ieyasu, enshrined after his death as Tōshō Daigongen, was revered as "Shinkun."

Second, this flight came to be told as the origin of the Iga-mono's service to the Tokugawa house. The Iga-mono under Hattori Hanzō served the Edo shogunate as Iga dōshin.

Third, this event shows the ultimate test for a Sengoku warlord: how to conduct oneself in the power vacuum after the Honnōji Incident. Hideyoshi moved swiftly to defeat Mitsuhide and seized the initiative over the realm. Ieyasu built up his strength and displayed its results eighteen years later at Sekigahara. The contrasting actions of the two men reflect the essence of power politics in the late Sengoku period.

From the Iga-goe of Tenshō 10 to the founding of the Edo shogunate in Keichō 8 (1603), Ieyasu spent 21 years bringing the realm into his hands. The Shinkun Iga-goe, as a historical event standing at the starting point of that long course, shines brilliantly in Japanese history.