In the middle of the Onin War, Mochikiyo, the Kyogoku clan's soryo (heir), and Katsuhide KYOGOKU, the legitimate child (first-born son), had died of illness in quick succession; therefore, the Kyogoku clan had to name the heir.
応仁の乱の最中に京極氏は、惣領・持清と嫡子（長男）・京極勝秀が立て続けに病死した為、跡目を決めなくてならなくなくなった。