Initially, Roju was called Toshiyorishu (literally, old persons), and the name of Toshiyorishu was generally used among Hatamoto (direct retainers of the bakufu, which was a form of Japanese feudal government headed by a shogun).
当初、老中は年寄衆と呼ばれていたということで、旗本の間では年寄衆という呼称で定着した。