The roots of the conflict lay in the rival claims of Queen Rhaenyra Targaryen and King Aegon II Targaryen, sparking a bitter civil war across the Seven Kingdoms. Rhaenyra’s faction, known as the blacks, possessed more dragons than Aegon’s greens. However, their power was primarily centered around Dragonstone, not mainland Westeros.
House Tully remained neutral due to internal discord between Lord Grover Tully and his grandson, Ser Elmo. To consolidate support in the Riverlands, Rhaenyra’s husband, Prince Daemon Targaryen, proposed Harrenhal as a strategic rallying point. Unfortunately, Harrenhal was under the control of Larys Strong, a staunch green supporter of Aegon.
As Jacaerys and Lucerys Velaryon sought allies and Corlys Velaryon secured Blackwater Bay, Rhaenyra entrusted her husband with the command of the assault on Harrenhal, marking the beginning of the bloody Dance of the Dragons.
As Lord Larys Clubfoot served as Aegon II’s master of whisperers in King’s Landing, his great-uncle, the elderly Ser Simon Strong, acted as Larys’s castellan at Harrenhal. When Prince Daemon Targaryen, riding his dragon Caraxes, arrived at the top of Harrenhal’s Kingspyre Tower, he evoked the memories of the castle’s tragic past, recalling how Aegon I Targaryen and Balerion the Black Dread had burned Harrenhal, leading to the downfall of House Hoare.
Ser Simon, sensing the inevitable, struck his banners and surrendered the castle to Daemon. In the aftermath, Simon and his grandsons became hostages, and the blacks claimed the wealth of House Strong.
The loss of Harrenhal rattled Aegon II, bolstering the morale of the blacks. Subsequently, they secured victories at the Burning Mill and Stone Hedge. River lords, including House Blackwood, assembled at Harrenhal, where Daemon sanctioned the use of Blood and Cheese to avenge the death of Rhaenyra’s son, Lucerys.
Upon learning that Ser Criston Cole and Prince Aemond Targaryen had left King’s Landing to reclaim Harrenhal, the blacks abandoned the castle. The rivermen marched to meet Lord Jason Lannister’s westermen at the Red Fork. Although Criston and Aemond recaptured Harrenhal without bloodshed, their absence played a role in the fall of King’s Landing to Daemon and Rhaenyra. Aemond ordered the executions of Simon Strong and his kin, sparing only Alys Rivers. The Dance of the Dragons continued its brutal course.