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.
During the First Battle of Tumbleton, Ser Ulf White and Ser Hugh Hammer defected from the blacks to the greens and had their 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 Ser Hobert Hightower gathered eleven other lords and landed knights to the cellar of a Tumbleton inn called the Bloody Caltrops, where they debated over how and when to kill the Two Betrayers. The drunkard Ulf would be an easier target, as 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 drunkenly 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 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.
- Marq Ambrose, slain during the Second Battle of Tumbleton
- Lord Owen Fossoway, slain during the Second Battle of Tumbleton
- Lord George Graceford, one of the 3 Caltrops to survive the Dance of the Dragons
- Ser Hobert Hightower, died alongside Ulf White when he shared the poisoned wine meant for Ulf
- Lord Leygood, slain during the Second Battle of Tumbleton
- Ser Tyler Norcross, slain during the Second Battle of Tumbleton
- Lord Unwin Peake, one of the 3 Caltrops to survive the Dance of the Dragons
- Ser Victor Risley, one of the 3 Caltrops to survive the Dance of the Dragons
- Richard Rodden, took an arrow during the Second Battle of Tumbleton and died the following day
- Ser Jon Roxton, killed by Hugh Hammer's men after killing Hugh during the Second Battle of Tumbleton
- Three other lords and landed knights, slain during the Second Battle of Tumbleton
Men may plot and plan and scheme, but they had best pray as well, for no plan made by men has ever withstood the whims of the gods above.—writings of Gyldayn