Background
Kagenori Obata was born in 1572. He was the son of a former retainer of Katsuyori Takeda, lord of Kai Province (Yamanashi Prefecture).
Kagenori Obata was born in 1572. He was the son of a former retainer of Katsuyori Takeda, lord of Kai Province (Yamanashi Prefecture).
Kagenori Obata became a priest (1595), left Hidetada and studied military science from former retainers of the Takeda Clan. He served Harunaga Ono, a warlord of the Toyotomi Camp, concealing his identity (1615). Soon after he fled from Ono's service and informed Ieyasu at Fushimi of the Toyotomis' circumstances Ieyasu rewarded him with a fief of 1,500 koku. He was the first samurai to make strategy his family profession. Among his disciples were such distinguished strategists as Soko Yamaga and Ujinaga Hojo.
After the Takeda family was destroyed (1582) and his parents died he served Ieyasu Tokugawa and became 'a page of Hidetada, Ieyasu's son.