XIII Corps, under Eighth Army, played a key role in the fourth and final battle of Monte Cassino in May 1944 and later came under command of the U. S. Fifth Army, under Lieutenant General Mark W. Clark, fighting on its right wing in the assaults during the autumn and winter of 1944 on the Gothic Line and central Apennines. On 1 June 1944 Kirkman was made a Companion of the Order of the Bath (CB). XIII Corps later returned to Eighth Army command in January 1945 but Kirkman himself, whose rank of lieutenant general was made temporary on 20 January 1945, was invalided back to the United Kingdom with severe arthritis in March, command of XIII Corps going to Lieutenant General Sir John Harding, formerly Alexander's chief of staff.