The Axis attack began at dawn on 20 June 1941, led by assault engineers and supported by air attacks. The Afrika Korps had the most success, and the Italian XX Corps followed through a break in the defenses created by the Afrika Korps. A series of rapid movements within the fortress itself paralyzed the Allied response, and by the evening of 21 June, the last of the garrison had surrendered, destroying as many supplies and as much of the port facilities as possible beforehand.
The Allies had 32,220 troops captured, including virtually all of the 2nd South African Division. Axis forces also secured invaluable supplies, including nearly 2,000 tons of fuel, 5,000 tons of food, 2,000 vehicles, and large amounts of ammunition (including both German and Italian stores). This booty was of immense help to Rommel in resuming his eastward drive, although there was considerable squabbling over its distribution.
The fall of Tobruk provided a supply port for the Axis forces close to the front. Moreover, it was a tremendous psychological blow to the Allies. With this and the Axis victory at Gazala earlier in the campaign, Rommel and the Italian commander in chief in Libya, General Ettore Bastico, were promoted to field marshals. Conversely, the Allied defeat led Britain's Middle Eastern commander, Auchinleck, to remove Ritchie from command of Eighth Army on 25 June and assume that position himself. The fall of Tobruk also led Adolf Hitler to delay an assault against Malta in favor of allowing Rommel to continue his advance eastward toward the Nile, setting the stage for the great First Battle of El Alamein. Jack Greene
Greene, Jack, and Alessandro Massignani. Rommel's North Africa Campaign. Conshohocken, PA: Combined Publishing, 1994.; Montanari, Mario. Le Operazioni in Africa Settentrionale. Vol. 3, El Alamein. Rome: Ufficio Storico, 1989.