Jang Bo Go (Choi Soo Jong) was a slave from Shilla (a Korean dynasty that lasted from 57 B.C. until 935 A.D.) He was sold in China during the Tang Dynasty, where he was trained as a gladiator-slave. Through hard work and perseverance, he made it back to Shilla and became a successful sea merchant. The sea passage at the time was plagued by pirates and Jang Bo Go went head to head with them in battles and managed to keep the pirates at bay. (imdb)