The Treasons of Tumbleton were a series of defections within the forces defending Tumbleton that helped turn a hard-fought battle into a royalist victory and the destruction of the town. The episode is remembered less as a single, fully understood conspiracy than as a convergence of hidden loyalties, disputed motives, and the sudden loss of the defenders’ most powerful advantage: their dragons.

Background and Uncertainty

Tumbleton had become a major gathering place for Rhaenyra Targaryen’s supporters. Its defenders included riverlords and other fighters who had rallied beneath her banners, while the arrival of Vermithor and Silverwing, ridden by Hugh Hammer and Ulf White, strengthened the town’s prospects against Lord Ormund Hightower’s advancing army. The defenders’ numbers are uncertain: one account gives them nearly nine thousand, while other chroniclers offer totals ranging from six thousand to twelve thousand. Whatever the exact count, Lord Hightower’s host was larger. The circumstances of the betrayals remain contested. The chronicle states that some people entering Tumbleton as refugees from the advancing army may actually have been sent ahead to infiltrate the defenders. It identifies Owain Bourney and Roger Corne as secret supporters of Aegon II, but also stresses that their treachery alone would have had little effect without the decision by Ulf White and Hugh Hammer to change allegiance. The account thus distinguishes between possible advance infiltration and the more consequential defections of the two dragonriders, without claiming that every detail of a coordinated plan is known.

The Dragonriders Change Sides

Mushroom supplies much of the surviving account of Ulf White and Hugh Hammer and presents both men as poorly suited to loyalty or restraint. His explanation is that they chose to join Lord Hightower only when they saw the size of his army: its spearpoints seemed to stretch away for leagues. Their earlier willingness to face danger at the Gullet complicates that explanation. The chronicler also suggests that concern about fighting Prince Daeron Targaryen and his dragon, Tessarion, may have influenced them, though this remains speculation; Vermithor and Silverwing were both older and larger than Tessarion. Other accounts attribute the change of allegiance to ambition rather than fear. After the Gullet and the fall of King’s Landing, Ulf and Hugh had received knighthoods, but they reportedly wanted lordships and considered the holdings granted by Rhaenyra inadequate. A proposal to grant them the lands and castles of the executed Lords Rosby and Stokeworth through marriages to the lords’ daughters did not proceed: Rhaenyra instead allowed the executed men’s sons to inherit. Storm’s End and Casterly Rock were also discussed as possible rewards, but the queen did not grant them. In this telling, the men’s dissatisfaction with what they had received, and with what they had been denied, made Aegon II’s cause a possible route to greater power. The possibility that promises from Aegon II’s party helped secure the defections is raised but not established. Lord Larys Strong, or one of his agents, may have conveyed such offers, yet the record cannot confirm it. The chronicler adds a reason certainty may be impossible: neither Ulf nor Hugh could read or write, leaving no written explanation from them. Their motives consequently remain divided among accounts of cowardice, fear of Tessarion, resentment, and avarice, rather than resolved into a single proven cause.

Battle and Collapse of the Defense

The defections unfolded amid a battle that had already begun to turn against Rhaenyra’s men. About six thousand defenders formed up under Garibald Grey to meet Lord Hightower in the field. They held for a time, but archery weakened their ranks and a charge by the opposing heavy horse drove survivors back toward Tumbleton. Red Robb Rivers and his bowmen covered their retreat. Then Roderick Dustin and the Winter Wolves sallied from a postern gate and struck at the attackers’ flank, fighting through a much larger force to reach Lord Ormund Hightower. Roderick killed Lord Ormund before dying himself, and the fall of the Hightower banners briefly raised the defenders’ hopes. The appearance of Tessarion did not initially end that hope: the defenders still had dragons of their own. But when Vermithor and Silverwing took to the sky and turned their fire on Tumbleton, the balance collapsed. The dragons that had been expected to protect the town now helped devastate it. Outside the walls, Prince Daeron Targaryen swooped down upon Tessarion, while the dragonriders who had changed sides attacked the town. The reversal was stark: the defenders’ most formidable strength became part of the assault against them. At the same moment, Roger Corne and his men revealed their allegiance by attacking defenders at the gates and opening them to Lord Hightower’s forces. Owain Bourney betrayed the defense inside the castle, killing Merrell the Bold. Their actions gave the attackers access from both the town gates and within the stronghold, turning the dragon attack into a wider collapse of resistance. The episode’s name therefore refers not only to Ulf White and Hugh Hammer’s change of allegiance, but to a chain of betrayals that helped make the defenders’ position untenable.

Sack and Aftermath

Tumbleton was burned and its population suffered extensive deaths and violence. The town’s defenders were overwhelmed; surrender did not ensure safety, and civilians were also subjected to brutal treatment. The destruction was not confined to the battlefield: the prosperous market town was reduced to ruins, and many people died while trying to escape by river. The account’s scale of devastation makes clear that the betrayal’s consequences extended far beyond the changing of military allegiance. Tumbleton never recovered its former size. Later members of House Footly attempted to rebuild on the ruins, but the replacement settlement remained only a fraction of the old town. Its smallfolk regarded the ground as haunted. In the narrative, that aftermath gives the Treasons their lasting weight: uncertain motives and secret political loyalties culminate not merely in a change of advantage between rival armies, but in the destruction of a community and the failure of its attempted renewal.