《资治通鉴·晋纪·晋纪三十二》
大家都说： 周朝与秦朝以前，天子都是由诸侯中升位的，他们都是用他们原来诸侯国的国号作为天下的国号。
皆曰： 周、秦以前，皆自诸候升为天子，因以其国为天下号。
They all stated unanimously, "From the Zhou dynasty and previous to the Qin dynasty, every天子(son of heaven) rose from being a feudal lord, each taking the name of their original feudal state as the dynastic title of the empire.