When Tenbun no ran (Tenbun Rebellion) occurred in the Date clan in the Sengoku period (Japan), Yoshimori MOGAMI became independent of the Date clan and began to become daimyo (Japanese territorial lord).
戦国時代(日本)に入って伊達氏内部に天文の乱が起こると、最上義守は伊達氏から独立して戦国大名の道を歩み始める。