House Bittersteel (The Black Dragon)

Spurned by the woman he loved in favour of his half brother Brynden, it was no wonder Aegor Rivers took his name as Bittersteel. A hard boy who grew into an even harder man, he was instrumental in convincing his elder brother Daemon to press his claim for the Iron Throne. In the war, Bittersteel was one of his brother's chief commanders alongside Quentyn Fireball, even managing to slay his half-brother and bitter rival Brynden 'Bloodraven' at the Battle of Redgrass Field. When Daemon Blackfyre took the throne, Bittersteel was given the lordship of Blackheart and the castle of Summerhall in reward for his service, and also to keep a watchful eye upon Lord Baratheon, who had never declared for either side during the war.

Bittersteel would soon overtake the High Lordship of Summerfield, the old title once held by House Toyne before their shortlived rebellion. But when House Dayne kidnapped Lord Yronwood for his 'disloyalty' to House Martell and his siding with the Blackfyres, Lord Aegor Bittersteel was the first to march south, demanding the release of Lord Yronwood or House Dayne would answer to him. The Daynes foolishly declined, feeling secure in their mountain fortress of Starfall, and soon Lord Yronwood perished from malnutrition. Hearing news of this, King Daemon issued a warrant for Lord Timeon Daynes arrest, but the Daynes again refused, raising their banners in defiance of the king. Bittersteel alongside other loyal Blackfyre vassal marched on Starfall, but Lord Timeon, like the coward he was, retreated into hiding and even managed to organize a kidnapping of King Daemon Blackfyre. Lord Timeon, unsatisfied with simply kidnapping a crippled man, executed the King, and thus doomed his house to ruin. For in retribution, when Starfall fell to Bittersteel, every Dayne that had been within the castle was executed personally by Lord Aegor Bittersteel. It is said that he took each of their heads north with him, and mounted them on spikes upon the walls of Summerhall, in warning against those who would dare challenge House Blackfyre.

With Daemon Blackfyre's death, his eldest son Aegon took the throne. He had been raised in Summerhall under the tutelage of Bittersteel, as his father had not yet trusted the machinations of King's Landing, knowing full well the danger of the city having grown up there as a boy. Due to their close relationship, Aegon held Bittersteel's council in great esteem, so when the question of what to do with Dorne after House Yronwood revolted against the new king arose the new King followed Bittersteel's advice in returning Dorne to House Martell, provided they could prove their loyalty to House Blackfyre.