Masquerade (2012)

Amid national chaos and fear for his life, tyrannical King Gwanghae orders his trusted councilor Heo Kyun to find a royal body double. He hires Ha-seon, a peasant mimic who bears a perfect resemblance to the King. When King Gwanghae collapses from a mysterious poison, Ha-seon reluctantly becomes a King. He must follow his conscience to save his country from collapse, avoid assassination, and pull off the biggest masquerade in history. K—CJ Entertainment