On arriving in North Africa, Horrocks' corps was ordered to defend the Alam el Halfa ridge in northwestern Egypt from an expected attack by the Afrika Korps. Concerned that heavy casualties would jeopardise his planned El Alamein offensive, Montgomery instructed Horrocks to repel Erwin Rommel's forces "without getting unduly mauled in the process". Horrocks prepared for a purely defensive battle, with his armour dug in around the ridge. When the Germans attacked on 30 August, they failed to lure the British tanks towards their 88 mm guns—a tactic that had previously been used with great success—and found themselves battered by both artillery and the Desert Air Force (DAF). The battle ended with the Germans in control of Himeihat hill, but at a high cost, and the Allied forces unwilling to try to re-take it after a failed attack by the 2nd New Zealand Division. The army's defensive success raised morale, and Horrocks was praised by his subordinate, Brigadier George Roberts, for his "wonderful knack of inspiring confidence and enthusiasm wherever he goes". Montgomery, too, was pleased, saying "he deserves great credit for his action on that day".