at the War Office. In the event, owing to the death of another officer, the War Office decided that Simpson could not be spared from his duties as Deputy Director of Military Operations, and de Guingand served as Montgomery's chief of staff for the rest of the war. Although common in other armies, the concept of a chief of staff was foreign to the British Army, where a staff was divided into separate general and administrative staff branches; at the Eighth Army headquarters the Chief Administrative Officer (CAO) was Brigadier Sir Brian Robertson, with Lieutenant-Colonel Miles Graham as his deputy. Under the chief of staff system, one officer was responsible for both operations and administration. This was a system that Montgomery strongly favoured; he had served as chief of staff of the 47th (1/2nd London) Division during the Great War. Montgomery moved the Eighth Army headquarters from Ruweisat Ridge back to Borg El Arab on the Mediterranean coast, about south west of Alexandria, where it was collocated with that of the Desert Air Force. De Guingand held a daily staff meeting at 07:00. He maintained personal contact with Robertson at Rear Army Headquarters and briefed Montgomery every night at 21:00 in the latter's map lorry. Ultra intelligence decrypted an appreciation by the German commander, Generalfeldmarschall Erwin Rommel, that indicated that he intended to attack in late August. The full moon needed for a major night movement was on 26 August, and a prohibition on reconnaissance near the Qattara Depression indicated that a flanking attack near there was likely. Montgomery fortified Alam el Halfa ridge and brought in the 44th (Home Counties) Division to defend it. De Guingand and Williams concocted a ruse whereby they prepared a fake "going" map indicating that an area of soft sand near the ridge was suitable for vehicles but it is uncertain as to whether the Germans were fooled. In any event, the German attack, delayed for several days by fuel shortages, was repulsed in the Battle of Alam el Halfa. De Guingand urged that the Eighth Army carry out an immediate counter-attack but Montgomery did not consider that it was ready for this and passed up the opportunity in favour of a set piece battle. Over the following weeks, de Guingand oversaw the preparations for the attack. When the preparations were complete, Montgomery decided that de Guingand looked tired and sent him back to