Ietsugu Sakai (1564-1619) was the daimyo of the Sakai clan of Mikawa Province who succeeded his father Tadatsugu Sakai in 1578. He was allowed to share a part of Ieyasu Tokugawa's name with the "Ie-" as a prize for loyalty, and was given the Usui Domain in Kozuke in 1590. In 1604 he was moved to the Takasaki Domain, and again was moved to the Takata Domain in Echigo in 1616. Later in his career, he fought in the Osaka Campaign as a vassal of the Tokugawa and was finally given the Matsuhiro Domain in Shinano the year of his death.