 Youzhou was first instituted as an administrative unit in 106 BC during the Han Dynasty.In 106 BC, Emperor Wu of Han organized the Western Han Dynasty into 13 province-sized prefectures, each administered by a "cishi" () or inspector.You Prefecture comprised the Shanggu, Zhuo, Guangyang, Dai, Bohai, Yuyang, Right Beiping, Liaoxi, Liaodong, Xuantu and Lelang Commanderies.