The Okura clan is said to have been progeny of the Emperor Ling (Han) in the Later Han Dynasty who was descended from the founder and first Emperor of the Earlier Han Dynasty, Gaozu (Liu Bang).
大蔵氏は前漢初代皇帝「高祖（劉邦）」の流れを汲む後漢の霊帝(漢)を祖とするという。