The Chôsokabe clan is believed to have been decended from the Chinese emperor Qin Shi Huang, and were respected Jitô (deputy administrators) of Tosa from the 12th Century and entered the 16th Century as vassals of the Ichijô clan, who were based in western Tosa. Chôsokabe Motochika succeeded in taking all of Shikoku by 1584 but submitted to Toyotomi Hideyoshi when the latter invaded the island the following year. The Chôsokabe lost their lands after Sekigahara (1600) to the Yamauchi.