Three consecutive imperial dynasties or the reigns of three successive emperors; also used modernly to refer to three successive bosses or administrations.

A veteran high official or senior statesman, especially one who served several reigns in imperial China

Three consecutive imperial dynasties or the reigns of three successive emperors; also used modernly to refer to three successive bosses or administrations.

A senior figure, founding member, or doyen of an organization, political party, or field of activity