Ogier the Dane
A hero in Carolingian romance, possibly based on a historical figure named Otker. He is non-Arthurian except for an account in Ogier le danois where Ogier is shipwrecked in the Mediterranean. Rescued by angels, he comes to the Island of Avalon, where he finds Morgan, Arthur, and Gawain still alive. He lives with Morgan in her palace for 200 years, begetting two sons upon her, before leaving.
Brewer says that Morgan once took Ogier to Avalon, gave him a ring of youth and a crown of forgetfulness, and introduced him to King Arthur. Two hundred years later, she sent Ogier to fight the Moors in France. He routed them and then returned to Avalon.