It took severe casualties, mainly because of obsolete British tank tactics, (especially charging anti-tank guns) but finally forced Erwin Rommel's Afrika Korps to withdraw to El Agheila in Central Libya. In spring 1942, Rommel had counter-attacked and driven the British back to Gazala, a few miles west of Tobruk. The plan of British Eighth Army Commander Neil Ritchie was to have XIII Corps hold the line, while XXX Corps would stop any attempt to outflank the position south of Bir Hachiem, held by the 1st Free French Brigade. They managed to slow Rommel's armour down and forced Rommel's tanks into "The Cauldron", the gap left in the British Lines by the destruction of the 150th Infantry Brigade, part of the 50th (Northumbrian) Infantry Division in late May 1942. British counterattacks attempted to crush it but failed. Eventually, the Free French at Bir Hachiem were forced to withdraw and Rommel was able to break out of the Cauldron. XXX Corps was forced to retreat to Mersa Matruh, held by the newly formed British X Corps. The Germans quickly broke through, surrounded X Corps (which fortunately for the British, managed to break out) and pushed XXX Corps back to El Alamein in June 1942.