King Uther has just died and everyone is in a frenzy because the king did not have an heir to the throne. No one knows Arthur Pendragon is his heir to the throne. Arthur is with his foster family and being treat badly.
Sir Kay Lies to his Father
Wart (Arthur) is what his foster family calls him. Wart was sent back to the Inn to fetch Sir Kay's sword. When he reaches the inn he realizes it's locked. Wart is Kay's squire.
The Truth Comes Out
After Arthur leaves the Inn he goes in search of a sword. He notices one just sitting in a stone and he goes up and pulls it right out. Little does he know he is now king.
Everyone is in the village for the tournament when Kay lies to his father and says he pulled the sword out instead of Arthur
Sir Kay is overcome with guilt and decides to tell his father the truth that Arthur was really the one who pulled out the sword.
Arthur was made king. Even though Kay and his foster father treated him badly he was loyal to them and allowed Kay to be in charge over his lands. He wouldn't even allow his foster father to bow down to him, instead he rose him up and told him not to do that. Throughout the story Arthur was always loyal and didn't treat them any differently like how they had treated him.