After Yoshimitsu ASHIKAGA stepped in the Yamana clan's succession dispute and gave a command for putting down Ujiyuki and Tokihiro in 1390, Ujiyuki was attacked and ruined by Mitsuyuki YAMANA in his home ground, Hoki Province, and fled to Bingo Province.
明徳元年（1390年）、山名家中の家督争いに介入した足利義満によって氏之・時熙兄弟に討伐令が下ると、氏之は山名満幸によって本拠地の伯耆国に攻め込まれ没落し、備後国へ逃れた。