From A Wiki of Ice and Fire
|House Blackfyre of King's Landing|
|Coat of arms||Gules, a three headed dragon breathing flames sable|
|Died out||+/- 256AL|
House Blackfyre is a semi-extinct noble house from the Crownlands. House Blackfyre was a cadet branch of House Targaryen, founded by Daemon Blackfyre, the legitimized bastard of King Aegon IV Targaryen. House Blackfyre is named for the sword of the same name.
Their sigil was a black three-headed dragon, breathing black fire on red, the Targaryen sigil with the colours reversed. Their motto is unknown.
House Blackfyre was founded by Daemon Blackfyre, the bastard-son of Aegon IV after he was legitimized by his dying father. Daemon inversed the Targaryen arms for his coat of arms and named the house after the sword Blackfyre that his father gave him when he was fourteen.  The sword had been the personal weapon of the first Targaryen king Aegon I and all his successors.
It is not known if lands were bestowed on Daemon.
In 195 AL Daemon and his friends and allies revolted against Daeron II, his half-brother, using the old rumor that Daeron was the son of Aemon the Dragonknight instead of Aegon IV and that the gift of the ancestral weapon Blackfyre proved that Aegon wanted Daemon to succeed him.
The Golden Company was founded in Essos by Aegor Rivers, a legitimized bastard of King Aegon IV, after he fled Westeros at the end of the rebellion. When Aegor saw all the exiled lords and knights signing on with other sellsword companies, and saw the support of House Blackfyre ebbing away, he created his own sellsword company.
The Second Blackfyre Rebellion took place in 212 AL. It never spread beyond the walls of Whitewalls, but several key Blackfyre supporters were killed. The remaining sons and their descendants attacked the Seven Kingdoms a number of times (as many as five Blackfyre rebellions have been mentioned).
The last attack was in 257 AL when Maelys the Monstruous, head of the Golden Company, joined forces with a number of ambitious men and invaded the Stepstones as a base for a future invasion of the Seven Kingdoms. Aegon V sent an army that defeated the rebels. Maelys the Monstruous was killed in single combat by Ser Barristan Selmy, who cut a bloody path though the Golden Company's ranks to get to Maelys.
The Female Blackfyre Line
According to Illyrio Mopatis the Blackfyres were extinguished in the male line when Maelys Blackfyre was slain by Ser Barristan Selmy.  What happened to the female line is not known, it should be safe to say that there are Blackfyre descendants in Essos who trace their ancestry through the female line. One of them could possibly be the Targaryen pretender.
References in the books
Dunk & Egg
- Daemon Blackfyre led the Blackfyre Rebellion.
- Daemon broke Lord Arryn's van at the Battle of the Redgrass Field, slaying Wyl Waynwood and the Knight of Ninestars and severely injuring Ser Gwayne Corbray of the Kingsguard. While protecting his fallen foes, Daemon and his two eldest sons, Aemon and Aegon Blackfyre, were slain by his half-brother Bloodraven and his Raven's Teeth.
- Daemon's remaining sons fled to the Free Cities with his principal supporter, Bittersteel.
- Daemon II Blackfyre instigated the Second Blackfyre Rebellion, but the rebellion was snuffed out quickly by Bloodraven before it could spread beyond Whitewalls.
- During the Whitewalls Tourney, Daemon II defeated Ser Franklyn Frey and Ser Galtry the Green.
- Daemon II had dragon dreams previously only found in members of House Targaryen.
|“||Aegon the Fourth legitimized all his bastards on his deathbed. And how much pain, grief, war and murder grew from that? … The Blackfyre pretenders troubled the Targaryens for five generations, until Barristan the Bold slew the last of them on the Stepstones. ||”|
|“||When Maelys the Monstrous died upon the Stepstones, it was the end of the male line of House Blackfyre. ||”|
References and Notes