the war with Takeda came in 1582 when a combined Oda-Tokugawa force attacked and conquered Kai Province. Takeda Katsuyori was defeated at the Battle of Tenmokuzan, and then committed seppuku. Death of Nobunaga In late June 1582, before the incident at Honnō-ji temple, Oda Nobunaga invited Ieyasu to tour the Kansai region in celebration of the demise of the Takeda clan. When he learned that Nobunaga had been killed at the Honnō-ji temple by Akechi Mitsuhide, this meant that some provinces, ruled by Nobunaga's vassals, were ripe for conquest. Later, Ieyasu traveled back to Mikawa for gathering his forces. With the help of his retainer and ninja leader Hattori Hanzō, Ieyasu first went through Sakai, then crossed the mountains of Iga Province, finally reaching the shore in Ise Province. He returned to his home Mikawa Province by sea. Ieyasu was mobilizing his army when he learned that Toyotomi Hideyoshi had defeated Akechi Mitsuhide at the Battle of Yamazaki. Ieyasu and Hideyoshi (1582–1598) After the death of Oda Nobunaga at Honnō-ji temple, the lord of Kai Province made the mistake of killing one of Ieyasu's aides. Because of this, Ieyasu promptly invaded Kai and took control. Hōjō Ujimasa, leader of the Hōjō clan responded by sending his much larger army into Shinano Province and then into Kai Province. Later, both Ieyasu and the Hōjō clan agreed to a settlement which left Ieyasu in control of both Kai and Shinano provinces, while the Hōjō took control of Kazusa Province (as well as bits of both Kai and Shinano provinces). In 1583, a war for rule over Japan was fought between Toyotomi Hideyoshi and Shibata Katsuie. Ieyasu did not take a side in this conflict, building on his reputation for both caution and wisdom. Hideyoshi defeated Katsuie at the Battle of Shizugatake. With this victory, Hideyoshi became the single most powerful daimyo in Japan. Conflict with Hideyoshi In 1584, Ieyasu decided to support Oda Nobukatsu, the eldest surviving son and heir of Oda Nobunaga, against Toyotomi Hideyoshi. This was a dangerous act and could have resulted in the annihilation of the Tokugawa clan, due to the fact that the Oda clan collapsed after Nobunaga's death. Tokugawa troops took the traditional Oda stronghold of Owari. Hideyoshi responded by sending an army into Owari. The Komaki and Nagakute Campaign was the only time any of the great unifiers of Japan fought each other. The Komaki