They are descended directly from Emperor Uda by his grandson Minamoto no Masazane , but were adopted by the Seiwa Genji. Minamoto no Nariyori, great-grandson of Masazane, is the first who took the name of Sasaki from his domain in Ōmi province. Hideyoshi, descendant of Minamoto no Nariyori, lost his parents young and became an orphan. He was adopted by Minamoto no Tameyoshi. He participated to the Hōgen war in which his father Minamoto no Tameyoshi was killed, and the Heiji war with his uncles, brothers, nephews, cousins and clansmen. After his brotherMinamoto no Yoshitomo was killed, and the defeat of the Seiwa Genji, he went North to ask Fujiwara no Hidehira of Mutsu province to give him shelter, but stopped at Shibuya and remained at that place for 20 years. When his nephew Minamoto no Yoritomo rose in revolt against the Taira, he with his four sons sided with him. He was killed during the Genpei war at the battle of Ōhara in Ōmi province fighting against the Taira clan. His descendants received from their Seiwa Genji cousins the title of shugo of Ōmi and other provinces, which they kept until the 16th century Sengoku Period wars. He is the ancestor of the Sasaki, the Rokkaku, the Amago, the Kyōgoku and the Kuroda clans. In 1868, at the end of the Tokugawa period :
There existed a certain Sasaki Shrine where Sasaki Yamagimi, a warlord, worshiped the god of ancestor's spirit. Following the middle of the Heian period, the shrine was used to worship the tutelary god of the Sasaki clan. It is said that through this, the "Ōmi-Genji Festival" is held every year on October 10 in respect of the Sasaki clan. One member of note amongst the Sasaki clan is none other than Sasaki Kojiro, the famous swordsman and rival of Miyamoto Musashi. The favorite technique of Kojiro was his "Tsubame Gaeshi", in which he attempted to use on Musashi throughout their duel. It is also known that the Sasaki clan apparently was a political obstacle to that of the Hosokawa, and the defeat of Kojiro would be a political setback to his religious and political foes.
Genealogy
Explanatory notes The bold-faced type is a master. The "〇" mark is a person who participated in Yoritomo's rising in arms. ∴ Emperor Uda ┃ :ja:敦実親王|Prince Atsumi ┃ Minamoto no Masazane ┃ :ja:源扶義|Sukenori ┃ Nariyori ┃ :ja:佐々木義経|Noritsune ┃ :ja:佐々木経方|Tsunekata ┃ :ja:佐々木爲俊|Tametoshi ┃ Sasaki Hideyoshi ┣━━━━━━┳━━━━━━━┳━━━━━━━┳━━━━━┓ 〇:ja:佐々木定綱|Sadatsuna 〇:ja:佐々木経高|Tsunetaka 〇:ja:佐々木盛綱|Moritsuna 〇Takatsuna Yoshikiyo ┏━━━━━━┳━━━━━┳━━━━━┫ ┃ ┃ ┃ ┣━━━━━┓ :ja:佐々木広綱|HirotsunaSadashigeHirosada:ja:佐々木信綱|NobutsunaTakashigeKaji Nobuzane Shigetuna :ja:佐々木政義|Masayoshi :ja:佐々木泰清|Yasukiyo ┏━━━━━━┳━━━━━━━━━━━╋━━━━━━━━┓ ┏━━━━━┳━━━━━┫ Shigetsuna Takanobu Rokkaku Yasutsuna Kyogoku Ujinobu Yoriyasu Yoshiyasu Muneyasu
