Segrave, however, on 28 December 1297 received letters of protection for himself and his followers, on their proceeding to Scotland on the king's service, and he subsequently fought in the Falkirk campaign. In 1299 he was again summoned to fight against the Scots. In 1300 he was once more in Scotland, taking a conspicuous part at the siege of Caerlaverock, representing Bigod in this campaign also. In 1301 Segrave attended the parliament at Lincoln and was one of the signatories of the letter of the barons to the pope, dated 12 February. On 5 August 1302 he was appointed to the custody of Berwick Castle of Berwick-on-Tweed. On 29 September he was ordered to make a foray into Scotland as far as Stirling and Kirkintilloch. After November the truce with the Scots ended, and Segrave was entrusted with the custody of Scotland.