Harrenhal had become the greatest stronghold of Rhaenyra Targaryen's power since Prince Daemon had won the keep. Its importance rivaled even Dragonstone, where the Queen herself resided. Unlike Dragonstone, however, Harrenhal was defended by a single dragon, Caraxes, the Blood Wyrm. Since the death of her son Prince Lucerys and the capture of her sister, Queen Rhaenyra had become increasingly protective of her family. Her oldest son, Jacaerys, had long been away recruiting for his mother's cause and the Prince Daemon was all but ungovernable. Aside from those two, however, the Queen kept her remaining dragonriders, her son Joffery and stepdaughter Baela, with her at Dragonstone. Dragonstone also boasted several wild dragons which served as further deterrents. In keeping the island so safe, the Queen left herself vulnerable to attacks on other fronts.
That being said, no man could question that King Aegon and his brother would find a formidable foe in Prince Daemon Targaryen. The Rogue Prince was one of few living Westerosi knights that had experienced war. The long, peaceful reigns of Kings Jaehaerys and Viserys had not led to many opportunities for the young men of the realm to test their mettle. Daemon's own battle experience was acquired in a war not endorsed by his sovereign. He and Corlys Velaryon, the Sea Snake, had allied to take the Stepstones of their own volition.
Prince Aemond Targaryen, another second son with a taste for battle, was considered by many a second Daemon. The young prince shared his ferocity and his cunning, it is true. Aemond Targaryen, though, lacked his uncle's experience and thought, perhaps, too highly of himself. When he approached Harrenhal with his brother the king, Aemond declared that he would face Prince Daemon alone and leave King Aegon to handle the Rhaenyra's troops. Vhagar, he likely thought, would be more than a fair match for Caraxes.
As they neared Black Harren's keep, Prince Aemond rode ahead of his brother and tempted his uncle into a fight. The two quickly disappeared from visibility into the skies above. Once they were out of sight, King Aegon descended. He began by burning the men in the training yard and those camped in the area surrounding the keep. Even as Sunfyre's flames charred the men's corpses, more ran out to replace the men. These runners were not armed, however. They were simply trying to flee, knowing that if they were to stay in the keep, they would surely be cooked as Black Harrren was. King Aegon turned Sunfyre's flames upon these men as they retreated. Only one for every ten who ran escaped to tell the tale. This survival rate, though low, perhaps proves the wisdom of the men who fled as it is far higher than can be said of the men who stayed within Harrenhal.
With Prince Daemon gone to battle, leadership within the keep fell to the newly invested Lord Walter Tully, Queen Alysanne's husband whom Aegon hated with great fervor. It is not known how the Lord Paramount of the Trident died or if he had even known of his wife's recent death. Some of the men who fled reported seeing archers on Harrenhal's outer wall fire at the dragon. Their arrows would've been all but futile. Unlike the Red Keep, Harrenhal was not armed with any weapons that could be used to fight off a dragon.
Rhaenyra's forces had lost nearly 60,000 men, mostly crownlanders and rivermen, by the time Sunfyre ceased burning. It was a blow that would take years to recover from. King Aegon, finally satiated, rose to find his brother and uncle still locked in battle. Prince Aemond was wounded, the left side of his face mildly charred by dragon fire, but was clearly determined to keep fighting. Even when his king ordered him to turn back from the fight, the prince and his great dragon only did so after getting one more slash of claws in. King Aegon's Sunfyre blasted a great wall of fire for coverage and fled with his brother in tow.
This decision is surprising still to many scholars and enthusiasts. King Aegon was not a man of temperance by nature. It should be remembered, however, that King Aegon had left the body of his beloved wife unrecovered back in King's Landing. By the time he returned to the capital, Silverwing had passed from her wounds and he ordered both corpses be recovered and given proper burnings in the Targaryen tradition.
There is still much more to the story of Dance of the Dragons, but that is beyond the purview of this short book, which has intentionally focused on the controversial figure of Queen Alysanne Targaryen II. It should be said, however, that the queen's loss continued to be felt by King Aegon, Queen Rhaenyra, and others as the war continued. Her two nephews by marriage, Kermit and Oscar Tully, would become some of Rhaenyra's strongest supporters in the future. They, alongside their friend Lord Benjicot Blackwood, became known as the Lads for their youth. The Lads would go on to defeat Lord Borros Baratheon at the Battle of the Kingsroad, clearing the way for the invasion of King's Landing that indirectly led to King Aegon II Targaryen's death.