He was appointed Deputy Director Medical Services XXX Corps, but quickly moved up in February 1943 to be Deputy Director Medical Services of Eighth Army, at the point when it came under the new 18th Army Group to allow co-ordination between British-led allied forces and the Americans. As DDMS, Eighth Army and by then a Brigadier (temporary), under Field Marshal Montgomery, he was involved in the planning and execution of Operation Husky, the invasion of Sicily in July 1943 which at that point was the largest amphibious assault ever mounted. He was Mentioned in Dispatches "in recognition of gallant and distinguished services in Sicily" for his work in this period. From July 1943 to 1944 he was Deputy Director Medical Services 3rd Advance Base.