Yamana Sōzen

Who was Yamana Sōzen?

Yamana Sōzen, was originally Yamana Mochitoyo before becoming a monk. Due to his red complexion, he was sometimes known as Aka-nyūdō, 'the Red Monk'. He was one of the daimyo who fought against Hosokawa Katsumoto during the Ōnin War in Kyoto.

Yamana Sōzen was born to Yamana Tokihiro, head of the Yamana clan. Tokihiro was the shugo governor of Tajima, Bingo, Aki, and Iga provinces. Tokihiro, who was often in bad health, retired in 1433 and passed his numerous lands to Sōzen. Sōzen went on to defeat Akamatsu Mitsuhide in the Kakitsu Incident, and became governor Harima Province the same year.

The Yamana clan had seen many defeats over the years, while the Hosokawa clan was one of the three families which controlled the position of kanrei, deputy to the Shogun. Thus, Yamana Sōzen resented the wealth and power enjoyed by his son-in-law, Hosokawa Katsumoto. Unwilling to engage him in open warfare until he was sure of his strength, Yamana chose to intervene in a number of succession disputes and other political affairs, thwarting Hosokawa's plans and desires, and slowly gaining allies for himself.

In 1464, a succession dispute erupted over the shogunate itself. The Shogun, Ashikaga Yoshimasa, was considering retiring. Hosokawa supported the Shogun's brother, Ashikaga Yoshimi as the successor, and so Yamana chose to support Ashikaga Yoshihisa, the Shogun's infant son. In 1466, both sides having spent several years gathering forces, both Yamana and Hosokawa felt ready to engage the other, and skirmishes began to break out.