Mordred was born to Arthur Pendragon and his half-sister Morgause. He was conceived through the trickery and magic of his aunt, Morgan le Fay. Morgan cast a spell on her siblings to make Morgause look like the woman of Aurthur's dreams and made Aurthur look like Morgauses dream man. The half-siblings slept together resulting in an evil incest child named Mordred. Morgan Le Fey took him under her wing and treated him like her son teaching him little magic but gifting him with incredible physical skills to be a great warrior. Morgan and Mordred constantly plotted against King Arthur and then declared war on him. King Arthur and Mordred battled and King Arthur killed Mordred but not before Mordred mortally wounded him. While Arthur was carried to Avalon Mordred was left on the battle field to die.
Mordred is based on the character of the same name from the Arthurian lore. He was adapted to comics by Stan Lee and Joe Maneely and first appeared in The Black Knight #1.
Major Story Arcs
Into the Marvel Universe
Many years later, Mordred was seen again, seemingly returned to life by Morgan le Fey. He encountered the superhero team known as the Avengers when they where transported into a different mid-eval reality. Mordred stood at Morgan le Fey's side, but where eventually defeated.