[3] In 1336, during a period of illness, his father proposed to give him lands worth 400 marks a year, including the manor of Harewood in Yorkshire, to enable him to serve Edward III with six men-at-arms.

[4] In 1342 his father became a Franciscan friar, and is thought to have been ordained a priest; in consequence, on 23 March 1342, the Lisle lands were taken into the King's hands.

[4] He returned to England, but on 20 January 1345, he was preparing to depart for Gascony with Henry of Grosmont, 1st Duke of Lancaster, then Earl of Derby.

He took part with Walter de Mauny in the defence of the English fortress at Aiguillon, and was Captain and Warden of St Sauveur.

With his retinue of six knights, eleven esquires and twenty-three archers, Lisle fought at Crecy in the second battalion under William de Bohun, 1st Earl of Northampton.

In August 1349 and October 1350, the arrangements for his £200 annuity were altered, with the king granting him custody of the lands and heir of Gilbert Pecche as part payment.

[9] On 8 July 1355, he was pardoned for the death of Sir John de Goys, and sailed for Gascony with the King's eldest son, Edward the Black Prince.