Kesselring was critical of Rommel's performance in the Battle of Bir Hakeim, a vital position held by the 1st Free French Brigade that formed the southern pivot of the British Gazala Line. Rommel called for, and Kesselring provided, air support, but the infantry assaults failed to capture the position. Kesselring attributed this to faulty coordination between the ground and air attacks. The Luftwaffe lost 14 aircraft on 3 and 4 June, and Kesselring was concerned that the Army planned to have the Luftwaffe starve the position out. After a ground assault led by Rommel in person, and air strikes by 124 Stukas and 76 Junkers Ju 88s escorted by 170 Me 109s, Bir Hakeim was evacuated by the Free French on 10 June. For Rommel's capture of Tobruk on 21 June, Kesselring brought in additional aircraft from Greece and Crete. In June over 260 German aircraft were in North Africa, and 7,035 sorties were flown. Over 33,000 prisoners were taken when Tobruk fell. For his part in the campaign, Kesselring was awarded the Knight's Cross with Oak Leaves and Swords, but he lost his one-rank advantage over his subordinates; Rommel was promoted to "Generalfeldmarschall" on 22 June, and Ugo Cavallero became a Marshal of Italy on 1 July, followed by Ettore Bastico on 12 August.