Isabella's husband had been brought to England in 1360 as a hostage exchanged for the freedom of King John II of France, an English prisoner. They married on 27 July 1365, at Windsor Castle, by which time Isabella was in her thirties. Her father, Edward III, gave her a dowry of £4,000 and a large lifetime annual income, together with expensive amounts of jewellery and lands; de Coucy was restored to his family's lands in Yorkshire, Lancaster, Westmorland and Cumberland, and was released as a hostage without any need for ransom.