Meiji Restoration

(明治維新 Meiji Ishin) A period of political turbulence in Japan ended in 1868 with the end of the shogunate, and the return to government centered on the emperor. The Meiji era started in that year. One of the incidental effects was to disrupt the system of Go's four houses and eliminate the Godokoro post, because the government subsidy was cut off.

See also the Wikipedia entry.