Born the fourth son of Takeda Shingen in Kai Province. Because his mother was the daughter of Suwa Yorishige, he was originally intended to inherit the Suwa clan, but became the Takeda heir after his eldest brother Yoshinobu was disinherited and died. When Shingen died in 1573 he took over the family and commanded the powerful Takeda military force. At the Battle of Nagashino in 1575 he confronted the combined forces of Oda and Tokugawa, but against the enemy's new tactics making extensive use of firearms, the Takeda army centered on cavalry suffered devastating losses and lost many of its finest generals. With this defeat as the turning point the Takeda clan declined rapidly, and defections by retainers followed one after another. In 1582, attacked from three directions by Oda Nobunaga, Tokugawa Ieyasu, and Hojo Ujimasa (the Koshu Invasion), he lost Kai and Shinano in rapid succession, and Katsuyori, abandoned even by his retainers, committed suicide with his wife and children near Tennokuzan at Tano. He was 37.