When Ieyasu TOKUGAWA established the Edo bakufu, he took the posts of the family head of the Minamoto clan and Junnain Betto and Shogakuin Betto, and after that successive Shoguns continued to take the posts.
そして、徳川家康が江戸幕府を開いた際に源氏長者と淳和院・奨学院別当を兼務して以後、以後歴代の将軍に引き継がれることになった。