Emperor Goshirakawa, who had emerged victorious from the Hogen Rebellion that occurred in 1156, proclaimed the creation of a new government, called the "Hogen shinsei" (new government of Hogen), in the intercalary ninth month of 1156 as part of the switch to a new era name, Hogen.
保元元年（1156年）の保元の乱に勝利した後白河天皇は、同年閏9月に『保元新制』と呼ばれる代替わり新制を発令した。