Invincible Lee Pyung Kang (Korean: 천하무적 이평강; Hanja: 天下無敵李平岡; RR: Cheonhamujeok I Pyeong-gang), also known as Taming of the Heir, is a 2009 South Korean television series starring Nam Sang-mi and Ji Hyun-woo. In a modern retelling of the classic Korean folktale "Princess Pyeonggang and the Fool Ondal" in which a princess helps her timid husband transform into an outstanding general during the Three Kingdoms era, Lee Pyung-kang is a golf course planner who "tames" Woo On-dal, the prodigal son of a rich man. It aired on KBS2 from November 9 to December 29, 2009 on Mondays and Tuesdays at 21:55 for 16 episodes.