It was decided that, as Koshaku (公爵 commonly translated as duke), only Gosekke (the five families of the Fujiwara clan whose members were eligible for the positions of Sessho and Kanpaku) originated from kuge (court nobles) and the Tokugawa Shogun family originated from buke (samurai families) were eligible.
公家からは五摂家、武家からは徳川将軍家が公爵相当とされた。