A vassal of Arthur and Lord of the Castle of the Fens.
His daughter was desired by Merlin, and then, because of an enchantment cast by Merlin, by King Ban of Benoic, who slept with her and fathered Hector of the Fens. Because of her lost virginity, Agravadain had to deter any suitors. One of them, Sir Leriador, was so angry that he besieged the Castle of the Fens, but Agravadain triumphed.
Source
Vulgate Merlin | Written 1220-1235.