[Theory] Theory on previous yonko

[Sakazuki]

Ashura Douji was the yonko before kaido. He looks just like the drawing of the guy in the first four yonko. He was dethroned by the time kaido was introduced. . . Maybe

 

[chopstickchakra]

It does look a lot like that image lol but I thought the Yonkou system/title only came about since Rogers death and the only change was BB taking over WB. Were there Yonko before WB, Shanks, BM and Kaidou?