The 11th Army gained ground during mid-June, focusing their attention on the northern approaches to the city. Casualties were high on both sides as the month dragged on. Aware of the need to act before the German offensive of 1942 reduced the availability of reinforcements and supplies, Manstein ordered a surprise attack across using amphibious landings on 29 June. The operation was a success; Soviet resistance crumbled. On 1 July German forces entered the city while the Soviet forces conducted a disorganised evacuation, and Hitler promoted Manstein to "Generalfeldmarschall" the same day. The entire city was in German hands by 4 July.