The Four Sages (囲碁四哲) were four go players from the Edo period that are considered to be of Meijin class but who, by historical accident, did not become Meijin.
The four players were: Honinbo Genjo, Yasui Chitoku, Inoue Gen'an Inseki and Honinbo Shuwa. Of these four Shuwa is considered to be the strongest and Genan the weakest. Genjo and Chitoku, famously, being of exactly equal strength.
 Appreciating Famous Games by Shuzo Ohira p.128