After his master took Kyoto he was placed in charge of the capital.
Later he built a castle on Mt. Shiki in Yamato (Nara Prefecture) from where he mastered local lords and kept them from revolting in 1559.
It is said he later poisoned Yoshioki, the son of his master, to death out of jealousy and the following year after Chokei died he took advantage of Yoshitsugu’s (Chokei’s son-in-law and heir) youthfulness and became highhanded in his actions. Because of this, he was disliked by Shogun Yoshiteru Ashikaga, who planned to kill mm. In the ensuing battle, however, Yoshiteru was defeated and committed suicide at Nijo Villa in Kyoto, throwing Kyoto into disorder. When Nobunaga Oda entered Kyoto Hisahide surrendered to him and was given asylum in 1568.
Later Hisahide turned traitor and began attacking Nobunaga from his castle at Mt. Shiki, but was defeated and had to commit hara- kiri.