After Wudi's death, the strength of the maternal side of the imperial family grew and began to intervene in politics, where the leader of such forces was frequently given the title along with political power.
武帝没後、外戚の権力が強まり、政治に参与するようになると、外戚勢力のリーダーがこの職に任ぜられ、政権を握ることが多くなった。