Shima Sakon, also known as Shima Tomoyuki, was initially a retainer of Tsutsui Junkei. He left the service of the Tsutsui and later became a retainer of Ishida Mitsunari. He was one of Mitsunari's chief lieutenants during the Sekigahara Campaign. He quarreled just prior to the battle with Shimazu Yoshihiro when the latter suggested a night attack, which Shima opposed. He commanded 1,000 men at the Battle of Sekigahara but was struck by rifle fire and died on the battlefield.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005