Yoshinori strengthened the power of the shogunate after defeating Ashikaga Mochiuji in the Eikyo Rebellion of 1438.
Yoshinori was assassinated in 1441 by Akamatsu Mitsusuke in the Kakitsu Rebellion. He was succeded by his son, the 7th shogun Ashikaga Yoshikatsu, in the next year but the power of the shogunate fell into decline.