Mordred Timeline and Summary

Mordred is conceived under not-so-great circumstances, when Arthur sleeps with his sister, Morgause, by mistake.
He manages to escape the May Day massacre, which his father orchestrated to get rid of the risk of losing his kingdom. Raised as a deserted child, he makes his way back to court at age fourteen.
Mordred defends Sir La Cote Male Taylé against the insults of a rude woman who doesn't want him along on her quest. Nice.
Then he participates in the ambush and stabbing-in-the-back of Sir Lamerok. Not so nice.
Joining Aggravayne in exposing Launcelot and Gwenyvere's affair, Mordred helps to ambush Launcelot in Gwenyvere's chamber.
When Arthur travels to France to invade Launcelot's realm, Mordred forges letters announcing Arthur's death, crowns himself king, and tries to marry Gwenyvere.
At the Battle of Salisbury Plain, Mordred gives Arthur his death-wound before dying of the wound Arthur has inflicted on him.