Ser Aegor Rivers, frequently called Bittersteel, was one of the Great Bastards and a son of King Aegon IV Targaryen by his fifth mistress, Lady Barba Bracken. Aegor was the founder of a famed group of exiled sellswords, the Golden Company. In his personal arms, he combined the red stallion of House Bracken with black dragon wings from House Blackfyre, on a golden field.
Bing half-Targaryen, Aegor had purple eyes, but black hair. As an adult, he had a close-cropped beard. He looked like a warrior, being lean, light, and tall. Aegor's armor was well-made, though plain-looking, being grey-steel and black rings. On his helm was a horsehead with a horse's made flowing behind. His shield displayed his personal sigil: a stallion with black dragon wings, on a golden field, snorting fire.
Aegor was angry all of his life, and quickly irritated and offended. He did not smile, and especially loathed his younger half-brother, Brynden Rivers, and Brynden's mother, Melissa Blackwood, who had replaced Aegor's mother Barba Bracken as King Aegon IV Targaryen's mistress.