1: When King Arthur was little, Merlin the wizard took him away from his family.
2: Arthur was soon adopted and served his adoptive brother. He also spent a lot of time with animals. His brother was a jouster and his family went to a fair to watch him joust.
3: At the fair Arthur realizes that he forgot his brother Kay's sword and had to go back and get it but he couldn't find it.
4: When Arthur went to retrieve his brothers sword, he went by a sword stuck in marble that everybody was pulling at trying to get out.
5: Arthur thought maybe he could borrow it and then return it after his brother used it. So Arthur tried it and it turned out he released it from the marble and became King Arthur. The rule was who ever pulled it out, would become king, therefore Arthur became King Arthur.