He returned to the United Kingdom and, despite having lost three fingers from his left hand, recovered relatively quickly. On 10 November 1943 he was promoted to acting lieutenant general and assumed command of VIII Corps, which was to take part in the invasion of Normandy. Soon afterwards, however, he was posted to the Italian Front in January 1944 to become Chief of Staff to General Sir Harold Alexander, then commanding the 15th Army Group (later designated the Allied Armies in Italy (AAI) before reverting to 15th Army Group in December 1944). He was appointed a Knight Commander of the Order of the Bath on 16 June 1944 for his service in Italy, and promoted to the substantive rank of major general on 13 July 1944. He played a large part in the planning for Operation Diadem, the Fourth and final Battle of Monte Cassino that led to the capture of Rome and the destruction of a large portion of the enemy's forces and the subsequent fighting on the Gothic Line. He went on to take command of XIII Corps in Italy in March 1945, leading it through the Spring 1945 offensive in Italy, arriving in Trieste just after the German surrender in May and the end of World War II in Europe. He was also awarded the Legion of Merit in the Degree of Commander by Harry S. Truman, the President of the United States, for his conduct during the war on 14 May 1948.