Uther Pendragon

King of the Britons in the 5th century A.D. He is the son of Constantine III, brother to Aurelius Ambrosius and Constans. 
Uther takes command after his brother Aurelius is poisoned and dies, and upon becoming ruler of Logres, Uther quells a rebellion of kings led by Duke Gorlois. 
Uther Pendragon is the father of King Arthur, by Merlin's magic of his disguise in sleeping with Igraine, wife of Gorlois.