A nishiki-e woodblock print depicting a sumo bout (Japan Sumo Association)
Martial arts similar to sumo have been performed around the world since long ago. Some that remain today are ssireum in South Korea, boke in Mongolia, and yagli gures in Turkey. In Japan, figurines of sumo wrestlers have been unearthed dating back to between the third and seventh centuries, and the sport is mentioned in the myths and legends of the Kojiki and Nihonshoki (Japanese history books written in the eighth century). When it was time to plant the rice, sumo bouts were performed as a way to pray for a bountiful crop or to predict whether that year's harvest would be good. In the Nara period (710-794) and Heian period (794-1192), sumo became an event conducted at the imperial court, and bouts were performed in front of the emperor.
During the age of the samurai, physical strength was an important skill for warriors, and samurai families began to employ sumo wrestlers. It has been written that the warlord Oda Nobunaga was such a devotee of the sport that he gathered wrestlers together to hold tournaments every year.
The Ryogoku Kokugikan sumo arena (Japan Sumo Association)
Sumo basically took its present form in the Edo period. Matches were held to raise money to construct shrines and temples or to replace bridges, and the professional sumo wrestler was born. A sport that was once enjoyed only by the rich and powerful became popular among the masses. Sumo events were often held in Edo (now Tokyo), Osaka, and Kyoto, and the sport's popularity grew with the sales of color woodblock prints featuring sumo scenes and pictures of wrestlers. The government of the time, though, disapproved of fighting and often issued orders banning sumo.
For this reason, the organizers of sumo decided on a set of rules, including the creation of a list of 48 legal moves and the round ring that is still used today. A system of stables was created to train wrestlers.
As many aspects of old Japan remain in sumo, such as topknots, traditional dress, and ancient customs, professional sumo is more than just a sport; it's a living example of traditional Japanese culture. The wrestlers serve as cultural ambassadors when they take part in events overseas.