Like China, it had a Three Kingdoms period, which was dominated by Baekje, Silla, and Goguryeo.
One tomb of a king from this region is named for the depiction of a eight-legged, "Heavenly" horse found there. The fourth king of one dynasty from this region developed an alphabet still used today. A general from this region used (*) turtle-ships to repel a Japanese invasion in the 1590s. Like China, it had a Three Kingdoms period, which was dominated by Baekje, Silla, and Goguryeo. The Choson Dynasty ruled it into the twentieth century, during which it was split into two countries. For 10 points, name this peninsula whose "North" and "South" are still at war.
One tomb of a king from this region is named for the depiction of a eight-legged, "Heavenly" horse found there.
{Korean} peninsula [or {Hangook bando}; or Choson {bando}]