From July 1942 he succeeded Major General William Ramsden as General Officer Commanding (GOC) of the 50th (Northumbrian) Infantry Division, leading it in the First Battle of El Alamein, the Second Battle of El Alamein in late October and in the Tunisian Campaign at the Battle of the Mareth Line in March 1943, where it formed part of Lieutenant General Sir Oliver Leese's XXX Corps. However, he was relieved of his command in mid-April 1943 by General Sir Bernard Montgomery, the British Eighth Army commander, blamed for his division's relatively poor performance during the battle, although the blame was more a faulty plan than it was Nichols's fault. He was succeeded as GOC 50th Division by one of Montgomery's protegees, Major General Sidney Kirkman, who, like Horrocks, had been at the Staff College, Camberley alongside Nichols in the year below during Nichols's second year. For his services in the Middle East Nichols was twice mentioned in despatches.