Who is Alexander from Arthurian Romances and what is their importance?

Alexander is the son of the Emperor of Greece. He refuses to become a knight in his own land because he insists upon finding glory and valor away from his homeland. Alexander convinces his father to allow him to go to King Arthur in England, where he gives Arthur great gifts, spends liberally, and is well loved by everyone.

When Alexander joins King Arthur and Queen Guinevere on their journey to Brittany, he falls in love with the queen's maiden, Soredamours. When news of Count Angres' rebellion reaches Brittany, Alexander begs King Arthur to make him a knight, and King Arthur agrees.