During the Wars of the Roses, Lord Bonville formed a deep enmity with Thomas de Courtenay, 5th Earl of Devon (1414–1458), largely based on the wish of each man to be the pre-eminent power in Devon. Courtenay had as his secondary seat Colcombe Castle, only a few miles from Shute, and the proximity of their two estates served to fuel their enmity. They met decisively with their armed followers at the Battle of Clyst Heath, on 15 December 1455, at which Lord Bonville was defeated and after which the Earl sacked and pillaged Shute. Lord Bonville witnessed the killing of both his son and grandson by Lancastrians on the same day at the Battle of Wakefield on 30 December 1460, and was himself beheaded on 18 February 1461 after the Second Battle of St Albans.