During 1807, the Peninsula War was beginning and Edward was among the first of the British troops to fight in the Iberian peninsula, alongside his older brother William Granville Eliot, who was in another regiment. Edward now saw major military action over the next 5 years, including the Battle of Vimiero (following which he was promoted to captain, 27th Inniskillen Regiment of Foot), the Battle of Talavera, Battle of Bussaco, Defence of the Lines of Torres Vedras, Battle of Badajoz. During this period, he fought in the elite Lord Hill's Flying Brigade.