It is explained by the fact that Trollope began the period of the Wars of the Roses in Calais as Master Porter, a position he was appointed to in 1455, where the Earl of Warwick held the position of captain. When Warwick returned from France, Trollope came with him to beef up the Yorkist position at Ludlow. Unfortunately on the 12 October 1459 Trollope availed himself of the offer to swap sides and receive a pardon from Henry VI. He duly took his men across the lines and spilled the beans about Richard of York’s plans. York was forced to flee in the night and the people of Ludlow experienced first hand the problems of being on the losing side of a conflict .
We know that Trollope spent some time in France during the following year when the Lancastrians received a set back and we know that by December 1460 he was in Yorkshire. He and Somerset led the forces that defeated York at the Battle of Wakefield on the 30th December 1460. We don’t know whether he tricked York into believing that he had more loyal men than he thought or whether he lured York out into open ground as the chronicler de Waurin recounts before revealing his true colours.
What we do know is that he fought at the second Battle of St Albans where he was knighted. An account of his role was given in Gregory’s Chronicle. He was injured by a caltrop (a spiky device left on the ground to injure animals and men) so stood and fought on the same spot killing fifteen men. Six weeks later he was himself killed at the Battle of Towton in 1461 – Edward had specifically identified him as someone to be extinguished with the additional incentive of a reward of £100.
We also know that Trollope is an example of a man who benefitted from the Hundred Years War. Historians think that he came from County Durham originally and that his background was the dying industry. He rose because he distinguished himself on the battlefield, probably helped himself to any loot that was available and married well. His wife was further up the social ladder than him being the sister of Osbert Mundeford one of his superior officers. Elizabeth and Sir Andrew had two children that we know of – one, David, was killed at Towton with his father (he’s sometimes identified as Andrew’s brother) whilst the other, Margaret, married Richard Calle was was the Pastons’ bailiff (as in the Paston Letters).
Wagner, John A. (2001) Encyclopedia of the Wars of the Roses.