He led English and Dutch troops in Spain. He was created the sole commander of the land forces in April 1705 and joint-commander with Sir Cloudesley Shovell of the fleet on 1 May, after he had been reinstated a member of the privy council on 29 March. He arrived at Lisbon on 20 June 1705, sailed for Barcelona that August on an expedition for the conquest of Catalonia, and began to besiege the city. For some weeks, the operations were not prosecuted with vigour and Peterborough urged that the fleet should transport the troops to Italy, but the energetic counsels of the Archduke Charles of Austria at last prevailed and by 14 October the city fell into his hands.