Rommel attacked the Gazala Line on 27 May, swinging round the two southern boxes. 1st Armoured Division, positioned behind the line, was ordered south. The division's 22nd Armd Bde was ambushed and retired into the 'Knightsbridge' box, while 2nd Armd Bde attacked the German flank from the east; both brigades delivered some sharp blows to the enemy as they followed up. On 29 May the two brigades were involved in a violent tank and artillery action in a sandstorm. Over the following days the division was involved in fierce tank battles in what became known as the Battle of the Cauldron. 22nd Armoured Brigade was badly mauled on 5 June, while 2nd Armd Bde Group with 11th (HAC) RHA and attached units had been sent to reinforce 7th Armd Division. Once Rommel had reduced the southernmost box at Bir Hakeim,stubbornly defended until 10 June by the 1st Free French Brigade, he resumed his advance. On 12 June Eighth Army made a fresh attempt to move its armoured brigades south to attack the enemy, but although 2nd Armd Bde achieved its objective, the day was costly for the British. Next day 2nd and 22nd Armd Bdes held onto their positions east of Knightsbridge, but that night some of the remaining boxes had to be evacuated.