Williams was in England to assist in the fight against the Spanish Armada in 1588. Williams accompanied Sir Francis Drake in the expedition to Spain and Portugal 1589, and later fought on behalf of the French Huguenots. He met the Earl of Essex in 1589, and the two became close when they were sent by Queen Elizabeth to lead an army as allies of Henry of Navarre against the Catholic League during the Spanish occupation of Brittany in 1592. He went on to serve Henry against the League during the late 1580s and 1590s, scored a major victory at the Battle of Arques. After Essex returned to England Williams became overall commander of the English forces supporting Henry and "de facto" envoy of the Queen. Shortly afterwards he captured Aumerle with only 600 men. During the Siege of Rouen in 1592, he almost killed Albanian-Italian leader Giorgio Basta in personal combat, slicing his neck and driving him and his men from the field. These actions made Williams a famous hero in England, and pamphlets of his exploits were published. Sir Henry Umton stated that King Henry was full of praise for Williams and his men, "I never heard him give more honour to any service nor to any man than he doth to Sir Roger Williams and the rest".