History of sumo - 相撲
The history of sumo is linked to that of Japan. The earliest written mention of sumo is found in a book from 712, which is the earliest extant copy of Japanese writing. The book recounts a legend according to which possession of the Japanese islands was determined by a sumo fight.
According to the book, the gods Takemikazuchi and Takeminakata fought on the Sea of Japan coast, where Shimane-ken now stands, until one of them won. Thus, control of the archipelago was ceded to the Japanese people led by Takemikazuchi, who is said to have established the imperial family from which the current emperor would descend.
At this time, combat seems to be a rather basic, instinctive sport, practiced only by men. Sumo started out as violent with no illegal moves, often a real fight to the death.
In the 800s, the practice of sumo was considered a martial art, rules were established and techniques refined. It was practiced by the warrior class.
Sumo evolved gradually over the centuries until the Edo era, when ranks and official lists were introduced. Then in 1761, the first professional version of sumo was created and called "ozumo".
Modern sumo was born in 1927 with the merger of the Tokyo sumo association with that of Osaka.