Pembroke died in Picardy (at either Arras or Moreuil) on 16 April 1375, following his release from prison. Despite a contemporary rumour that he had been poisoned by the Castilians, more likely causes were the dire conditions of (at least the early years) his imprisonment and sickness and fatigue brought on by his hard years of confinement. Cockayne notes that, because Pembroke died in France, and the balance of his ransom was to be paid to du Guesclin after the earl had returned to England, du Guesclin never received the balance of the ransom.