Born the eldest son of Minamoto no Tameyoshi, Yoshitomo emerged early as the leader of the Bando warriors of eastern Japan. When his father sided with Retired Emperor Sutoku in the Hogen Rebellion of 1156, Yoshitomo fought for Emperor Go-Shirakawa and won, personally executing his own father and brothers to prove his loyalty. The reward he received fell far short of his expectations, deepening his rivalry with Taira no Kiyomori. In the Heiji Rebellion of 1159 he allied with Fujiwara no Nobuyori, imprisoned the retired emperor, and attempted to seize power. He was defeated by Kiyomori's forces and fled toward the east, but in January 1160 he was assassinated while bathing at Noma in Owari Province, betrayed by Osada Tadamune, the father-in-law of his retainer Kamata Masakiyo. He was 37. His tragic end and the fact that he fathered great figures including Yoritomo and Yoshitsune made him a favourite subject of later chronicles and tales of war.

He combined fierce temperament and robust warrior spirit with political judgments that at times revealed dangerous impatience. The ruthlessness that enabled him to execute his own father coexisted with burning anger at perceived injustice. Deeply trusted by eastern warriors, he had the qualities of a charismatic leader, but poor strategic judgment in the Heiji Rebellion proved fatal.

As the father of Minamoto no Yoritomo, Yoshitsune, Noriyori and others who brought the Kamakura Shogunate into being, he is an indispensable figure in the genealogy of samurai government. His tragic life is described in detail in the Heiji Monogatari and forms a crucial prelude to the world of the Tale of the Heike. His grave remains at Noma Daibo temple in Mihama, Aichi Prefecture.