During the Muromachi period (1336–1573), potentates employed semi-professional Go players, called Go-uchi () or Jouzu () who competed against other clans. At the end of the 16th century, Nikkai (Hon'inbō Sansa) served Oda Nobunaga, Toyotomi Hideyoshi and Tokugawa Ieyasu as a Go teacher, and in 1578 was recognized as the first "Meijin" of Go by Oda Nobunaga; he also became the first Hon'inbō. Around this time, free opening of the game started; before, the game started from a set position of several stones on the board.