Taneyoshi's family was the Miura clan, the powerful gokenin (an immediate vassal of the shogunate in the Kamakura and Muromachi through Edo periods), and he departed for the front with his older brother Yoshimura during the Shigetada HATAKEYAMA Rebellion and the Makishi Incident in 1205.
有力御家人の三浦氏一族で、元久2年（1205年）の畠山重忠の乱、牧氏事件に兄の義村とともに出陣。