The tale begins after Arthur is born. His parents, King Uther Pendragon and Duchess Igraine(who isn't the king's wife), decide to give Arthur to the wizard Merlin. The king does this to hide Arthur from his wife and prevent her from finding out about the affair.
The Blade in the Rock
Merlin decides to give Arthur to one of the knights, named Sir Hector. Arthur grows up with his adoptive brother Kay and is taught the skills of a knight.
"Knights of the Round Table"
Later on, when Arthur is older, he attends a jousting tournament his brother Kay was competing in. However, he accidentally forgets to bring Kay's sword.
The Betrayal
Wanting to find a sword for Kay, Arthur searches around until he finds one that is embedded in a chunk of stone. He pulls it out for Kay and everyone sees him doing so. It turned out that the sword was a magical sword called Excalibur and that the person that pulls it out of the rock becomes the high king of England.
As Arthur grew even older, he creates the "Knights of the Round Table," a force meant to protect the kingdom and its people. The round table represented equality among all the knights with no knight having greater authority than the other.
Later on, Arthur's wife cheats on him with his friend. Enraged by this betrayal, King Arthur and his friend, Lancelot, start a civil war. This leads to the death of Arthur and many other knights.