The appointment to Shogun refers to a ceremony where the Emperor granted the title of seii taishogun (literally, "great general who subdues the barbarians") as the head of a military government and to govern Japan.
将軍宣下（しょうぐんせんげ）とは、天皇が武家政権の長であり、日本国の統治大権を行使する征夷大将軍位を与える儀式のこと。