During the
barons' wars Zouche adhered to the king. He was appointed
Sheriff of Northamptonshire in 1261, remaining sheriff until 1264, and sometimes ignored the provisions of
Magna Carta by acting as justice itinerant in his shire and also in
Buckinghamshire and
Hampshire. In 1261, he was also made justice of the forests south of
Trent, and in 1263 king's
seneschal. In April 1262, he held forest pleas at
Worcester. He was constable of
Rockingham Castle in the years 1261 to 1264, and of
Northampton Castle in the years 1261 to 1263. On 12 December 1263, Zouche was one of the royalist barons who agreed to submit all points of dispute to the arbitration of
Louis IX. He was taken prisoner in the
Battle of Lewes. He escaped almost immediately and took refuge in
Lewes Priory, where he is said to have been found after the fight disguised as a monk. In the summer of 1266, Zouche was one of the committee of twelve arbitrators appointed to arrange the terms of the surrender of
Kenilworth Castle. On 23 June 1267, after the peace between Henry III and
Gilbert de Clare, 8th Earl of Gloucester, he was appointed warden of
London and
constable of the Tower from June 1257 to April 1268. In 1270, Zouche and
John de Warenne became involved in a dispute over two manors in Northamptonshire. On 19 June the trial was proceeding before the justices at
Westminster Hall, and la Zouche seemed likely to win the case. Warenne, on 1 July 1270 at
Westminster Hall, attacked both Zouche and his son. Zouche died of his wounds on 10 August 1270, while Warenne was fined heavily for the assault. ==Family and legacy==