Hoàng Tử và Kẻ Nghèo Hèn - The Prince and the Pauper (1977)

Tom Canty is a poor English boy who bears a remarkable resemblance to Edward, Prince of Wales and son of King Henry VIII. The two boys meet and decide to play a joke on the court by dressing in each other's clothes, but the plan goes awry when they're separated and each must live the other's life.