The Eighth Army was defeated in the Battle of Gazala and was driven eastwards toward the Egyptian border, leaving Tobruk isolated. The Prime Minister, Winston Churchill, placed great store on the symbolic value of Tobruk; an exchange of ambiguous signals between Churchill and Auchinleck led to the garrison being surrounded, rather than evacuated as intended. On 20 June the attacked Tobruk with massed air support, penetrated a weak spot on the eastern defensive perimeter and captured the port. Much of the garrison on the western perimeter had not been attacked but they were cut off from their supplies and transport, without the means to escape from Tobruk, the majority had to surrender; 33,000 prisoners were taken.
