The "Gazala Line" was a series of occupied "boxes" each of brigade strength set out across the desert with minefields and wire watched by regular patrols between the boxes. When General Erwin Rommel attacked on 26 May, 150th and 69th Bdes of 50th Division occupied two boxes: there was a gap of between 150th Bde at Sidi Muftah and 69th Bde to the north, and another gap of between 150th Bde and 1st Free French Brigade's box at Bir Hakeim to the south. The line was not equally manned, a greater number of troops covering the coast leaving the south less protected. 1st South African Division was nearest the coast, with 1st and 7th Armoured divisions waiting behind the main line as a mobile counter-attacking force. 2nd South African Division formed a garrison at Tobruk and 5th Indian Infantry Division (which had arrived in April to relieve 4th Indian Infantry Division) was held in reserve.