The earliest mention of the post is found in the record of the fourteenth year of the reign of the Emperor Kinmei in "Nihonshoki" (Chronicles of Japan), but it was only in later ages that a government-regulated organization was actually established.
『日本書紀』においては、欽明天皇14年条に登場するのが最古であるが、実際の官制整備は後代のことである。