TED-Ed Lesson: It was Christmas in Camelot and King Arthur was throwing a party. In the midst of the revelry, a towering knight proposed a game. He challenged the warriors present to attack him with his own axe. If they could strike him down, they would win his powerful weapon. However, he would be allowed to return the blow in one year. Dan Kwartler details the myth of Sir Gawain and the Green Knight.