The Caltrops were thirteen nobles from the Reach who plotted to kill the Two Betrayers during the Dance of the Dragons. They were called the Caltrops after the inn in Tumbleton, the Bloody Caltrops, where they met to conspire.
In the Treasons of Tumbleton, Ulf White and Hugh Hammer switched from the blacks to the greens and had the dragons Silverwing and Vermithor burn the town of Tumbleton. While the greens' commanders regrouped in Tumbleton and planned how to attack the black-held King's Landing, the two baseborn dragonriders proved difficult to deal with. Ulf desired Highgarden, while Hugh had designs on claiming the Iron Throne. Hugh wore a black iron crown, enraging Prince Daeron Targaryen. Ser Roger Corne knocked the crown off, which led to Hugh nailing three horseshoes to Roger's skull. Corne's supporters tried to intervene, resulting in three dead and twelve wounded.
The enthusiastic Lord Unwin Peake and the somewhat reluctant Hobert Hightower gathered eleven other lords and landed knights to the cellar of a Tumbleton inn called the Bloody Caltrops. They debated over how and when to kill the Two Betrayers. The drunkard Ulf would be an easier target, but Hugh was protected by lackeys. After much deliberation, they determined to kill the dragonriders and claim their dragons while in Tumbleton. Prince Daeron was brought to the cellar by Lord Owen Fossoway and given warrants for the execution of the Two Betrayers by Lord Peake. Daeron eagerly affixed his seal.
The Caltrops planned their coup against Ulf and Hugh to occur two days later. However, the greens' army was awoken on that designated day by an attack by Ser Addam Velaryon, beginning the Second Battle of Tumbleton. Ulf slept through the battle, but Hugh rushed to the stables so he could ride to Vermithor. However, Hugh was cut down there by Ser Jon Roxton. Despite wielding the blade Orphan-Maker, Jon was then slain by Hugh's men. Eight of the Caltrops were dead by the end of Second Tumbleton, including Owen Fossoway, Marq Ambrose, and Jon Roxton. Richard Rodden died from his wounds the following day, leaving only four plotters. However, these included the ringleaders, Unwin Peake and Hobert Hightower.
The next morning after the Second Battle of Tumbleton, Hobert Hightower met with Ulf to plan the attack on King's Landing and provided two casks of wine, Dornish red and poisoned Arbor gold. Hobert expected to sip the red while Ulf drank the gold, but the dragonrider was suspicious of Hobert's behavior and asked for the red to be saved for later. Rather than give up the surviving Caltrops, Hobert decided to drink the poisoned gold with Ulf, which killed both of them. Following Ulf's death, Lord Peake failed to find a dragonrider for Silverwing and decided to lead the diminishing green army away from Tumbleton and back to the heart of the Reach.
- Lord Unwin Peake
- Ser Hobert Hightower
- Ser Tyler Norcross
- Marq Ambrose
- Richard Rodden
- Ser Jon Roxton
- Lord Owen Fossoway
- Six other lords and landed knights