Admiral Yi Sun-sin was born in Geoncheon-dong, Seoul, Josun dynasty(Ancient name of Korea) on March 8, 1545. Owing to the poverty of his family, he moved to and grew up in his mother's hometown, Asan, in Chungcheongnam-do province. He became a warrior at the late age of 32, after failing the exam at the age of 28. When he arrived Jeolla-do province as the navy commander of western part of Jeolla-do province in 1591, he predicted the war with Japan. He disciplined the navy tightly and made the turtle ship, which had at least five different types of cannon and had a fully covered deck with iron spikes to shield from cannon fire and attempt to board the ship, for preparation of the war.