Due to the involvement of Kusuko and her brother, FUJIWARA no Nakanari, in 810 the Emperor issued an order to the nobles to move the capital city to Heijokyo (Heijo Palace), although the Emperor Kammu had previously issued an order not to move the capital from Heiankyo (Heian Palace), but after that he took actual control of politics.
薬子やその兄の藤原仲成の介入により、大同5年（810年）、平安京より遷都すべからずとの桓武天皇の勅を破って平安京にいる貴族たちに平城京への遷都の詔を出し、政権の掌握を図った。