He became king by pulling out the sword out of the stone
King Arthur is considered as a legendary British Leader. He is present in the medieval history and is said to have be the leader of Britain against the Saxon invaders during the early 6th century.
However, he is mainly considered as the character from the folklore and invented only through literature. His actual existence is disputed in the modern history. He was a Romano-British leader in the British Army and fought against the Anglo-Saxons in the late 5th to 6th century. Then he established his empire over Britain, Ireland, Iceland, Norway and Gaul.