400
Started the tradition of the belt ranking system.
What is Kanō Jigoro
He incorporated a system of Kyu and Dan into martial arts, but this system actually originated in a chess-like game called Go (Igo in Japanese, Weiqi in Chinese). He split his students first into two ranks (Unranked, or mudansha; and ranked, or yudansha), and instituted a belt system to recognize the difference between them. These were later divided into levels of Kyu (white belt) and Dan (black belt) based on the rankings in Go.