Eventually, after Maitland relinquished command due to illness, General Sir John Murray assumed command of the expedition in 1813. With him came an addition 12,000 men, the Anglo-Sicilian force contained approximately 16,000 men. They were opposed by Marshal Louis-Gabriel Suchet. Advancing, Murray's command, and the 1st battalion, encountered and defeated Suchet's forces at the Battle of Castalla on 13 April 1813. A month later, after besieging the city of Tarragona, the 1st battalion retreated offshore with the rest of Anglo-Spanish-Sicilian force when General Murray was fooled into believing that advancing French columns were significantly larger than they actually were. After Murray's relief and replacement by Lieutenant General Lord William Bentinck, the 1st battalion returned with the rest of the force to the region around Alicante. With the Duke of Wellington's victory at Vittoria, Succhet began a withdrawal from Valencia and Catalan. Bentick's force began its slow, ineffective pursuit.