Yoritomo, after the defeat and almost complete extermination of his family at the hands of the Taira clan, managed in the space of a few years to go from being a fugitive hiding from his enemies inside a tree trunk to being the most powerful man in the land. Defeating the Taira clan, Yoritomo became "de facto" ruler of much of Japan and founder of the Kamakura shogunate, an institution destined to last 141 years and to have immense repercussions over the country's history.