The term is used to contrast the period with the age of samurai government following the Kamakura period, and the name derives from the fact that political power was held by an imperial dynasty headed by an emperor.
鎌倉時代以降の武家政権の時代と比較して、政治の実権が帝王の統治する「王朝」すなわち朝廷にあったことに由来する名称である。