Minamoto no Yorimitsu
Watanabe no Tsuna was a samurai of the Saga Genji branch of the Minamoto clan, and his official name was Minamoto no Tsuna. He was the son of Minamoto no Atsuru (933-953) married to a daughter of Minamoto no Mitsunaka, grandson of Minamoto no Mototsuko (891-942), great-grandson of Minamoto no Noboru (848-918), and great-great-grandson of Minamoto no Tōru (822-895), son of the Emperor Saga (786-842), the 52nd Emperor of Japan. Tsuna established the Watanabe branch of the Minamoto clan, taking the name from his stronghold at Watanabe, in Settsu Province, and in 1020 he was appointed 'Tango no kami' (Governor of Tango Province). He was the stepgrandson of the Seiwa Genji and "Chinjufu-shōgun" Minamoto no Mitsunaka (912-997), and was companion in arms to his step uncle Minamoto no Yorimitsu (944–1021).