Who is the Black Dragon in A Knight of the Seven Kingdoms?

A Knight of the Seven Kingdoms episode 5 doesn't just give viewers a brutal trial of seven to prove Ser Duncan "Dunk" the Tall's (Peter Claffey) innocence. It also offers up an extended flashback to his past as an urchin in Flea Bottom — and that past includes a Westerosi history lesson.

After scavenging around a battlefield with his friend Rafe (Dune: Prophecy's Chloe Lea), young Dunk (Bamber Todd) remarks that "the war is over. The Black Dragon's dead." But what war is he talking about, and which Targaryen has the title of the Black Dragon? Let's break it down.

A Knight of the Seven Kingdoms references the Blackfyre Rebellion.

The war Dunk mentions is known as the Blackfyre Rebellion, a Seven Kingdoms-wide conflict that took place in 196 AC (after Aegon's conquest), 13 years before the Ashford Meadow tourney. Similarly to the Dance of the Dragons seen in House of the Dragon, the Blackfyre Rebellion was fought between members of House Targaryen.

On one side of the war was King Daeron II Targaryen, who is still on the Iron Throne by the time of A Knight of the Seven Kingdoms. Opposing him was his half-brother Daemon I Blackfyre, a legitimized Targaryen bastard.

Both Daeron II and Daemon were sons of Aegon IV Targaryen, the grandson of House of the Dragon's Rhaenyra and Daemon Targaryen (Emma D'Arcy and Matt Smith). Prince Daeron's relationship with his father was tense, as Aegon IV wanted to attack Dorne unprompted, while Daeron II (married to Dornish Princess Myriah Martell) urged caution.

During this time, Aegon IV earned his father of the year status by spreading rumors that Daeron II was a bastard and that he would choose a new heir. He heavily favored one of his bastard sons, Daemon Waters, going so far as to give him Aegon the Conqueror's sword Blackfyre after he won a tournament at age 12. Daemon took Blackfyre as his own name after that.

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Aegon IV never did appoint a new heir, but he did legitimize all of his bastard sons on his deathbed in 184 AC, setting the stage for maximum Targaryen chaos. It took 12 years, but in 196 AC, Daemon opted for open rebellion and made a play for the Iron Throne. His sigil was a black dragon on a red field, the inverse of House Targaryen's usual sigil, prompting him to be known as the Black Dragon.

Daeron II won out in the end thanks to a decisive victory in the Battle of Redgrass Field, which Egg (Dexter Sol Ansell) references in song back in episode 3. Both Daemon and his twin sons died in battle, but they were far from the last of the Blackfyre Pretenders. Others departed Westeros for the Free Cities, only to come back later to try and take the Iron Throne for themselves.

Spoiler alert: It doesn't quite work out, but that's a story for another time (and potentially another season of A Knight of the Seven Kingdoms).

New episodes of Knight of the Seven Kingdoms premiere Sundays at 10 p.m. ET on HBO and HBO Max.