By 1400 on 15 June, 1st SA Division and elements of the 50th Northumbian Division were close to Gambut, headed towards the Egypt frontier. At the same time, Ritchie had ordered the balance of Eighth Army to withdraw to the defensive positions at Mersa Matruh, some 100 miles east of the frontier, leaving Tobruk to hold out and threaten the Axis lines of communication in much the same way as in 1941 This became known as the Gazala Gallop. At dawn on 21 June, the Tobruk Garrison surrendered to the Axis forces. On the same day, 1st SA Division were ordered to withdraw a further 220 miles east, to El Alamein.