King Arthur's once most trusted knight and his wife, Queen Guinevere betrayed Arthur, which caused him to go to battle against Lancelot. But before going to battle King Arthur he let his nephew Mordred in charge of Camelot until he came back. But Mordred being greedy for power, he wanted the kingdom to himself, but later on it resulted in a sword fight between King Arthur and Mordred that ended both of their lives.