He was born to Amago Masahisa in 1553. In the next year, Katsuhisa's father and grandfather were killed by Amago Haruhisa and Katsuhisa became a Buddhist monk. After the Amago clan was overthrown by Mori Motonari in 1566, Yamanaka Yukimori supported Katsuhisa against the Mori clan in 1568.
He lost to Mori Terumoto at Nunobeyama in 1570 and fled to the island of Oki. Katsuhisa was later returned from Oki and captured Tajima and Inaba provinces, defending Kozuki Castle for Toyotomi Hideyoshi against the Mori clan. He was attacked by Kobayakawa Takakage and Kikkawa Motoharu, was defeated and committed suicide.
The article is originally from OpenHistory.