The Second Battle of El Alamein marked a major turning point in the Western Desert Campaign of World War II. The battle lasted from 23 October to 5 November 1942. The First Battle of El Alamein had stalled the Axis advance. Thereafter, Lieutenant-General Bernard Montgomery took command of the British Eighth Army from General Claude Auchinleck in August 1942.
Success in the battle turned the tide in the North African Campaign. Allied victory at El Alamein ended Axis hopes of occupying Egypt, controlling access to the Suez Canal, and gaining access to the Middle Eastern oil fields. The defeat at El Alamein marked the end of Axis expansion in Africa.
By July 1942, after its success at the Battle of Gazala, the Italo-German Panzer Armee Afrika, comprised of German and Italian infantry and mechanized units under Field Marshal Rommel, had struck deep into Egypt, threatening the British Commonwealth control of the Suez Canal. General Auchinleck withdrew the Eighth Army to within 50 miles (80 km) of Alexandria to a point where the Qattara Depression came to within 40 miles (64 km) of El Alamein on the coast. This gave the defenders a relatively short front to defend and secure flanks, because tanks could not traverse the Depression. Here in early July, the Axis advance was halted in the First Battle of El Alamein.
Eighth Army counter-offensives during July were unsuccessful as Rommel decided to dig in to allow his exhausted troops to regroup. At the end of July, Auchinleck called off all offensive action with a view to rebuilding the army’s strength. In early August British Prime Minister Winston Churchill and General Sir Alan Brooke, the British Chief of the Imperial General Staff, visited Cairo and replaced Auchinleck as C-in-C Middle East by General Sir Harold Alexander. Lieutenant-General William Gott was to command the Eighth Army, but was killed before taking command when the transport plane he was travelling in was shot down by Luftwaffe fighters; Lieutenant-General Bernard Montgomery became Eighth Army commander.
Faced with overextended supply lines and a relative lack of reinforcements, yet well aware of massive allied reinforcements in men and material due to arrive, Rommel decided to strike at the Allies while their build-up was still not complete. The two armoured divisions of Afrika Korps and a force made of the reconnaissance units of Panzer Armee Afrika spearheaded the attack, but on 30 August 1942, the Allies stopped them at Alam el Halfa ridge and Point 102. The attack failed in this second battle at the Alamein line, better known as the Battle of Alam el Halfa (commonly but incorrectly Alam Halfa); expecting a counter-attack by Montgomery's Eighth Army, Panzer Armee Afrika dug in.
The factors that had favoured the Eighth Army's defensive plan in the First Battle of El Alamein, the short front line and the secure flanks, now favoured the Italo-German defenders. Furthermore, Rommel had plenty of time to prepare his defensive positions and lay extensive minefields (approximately half a million mines) and barbed wire. Eighth Army would have to make a frontal attack against well-prepared positions, and Alexander and Montgomery were determined to establish a superiority of forces sufficient not only to achieve a breakthrough but also to exploit it and destroy Panzer Armee Afrika. In all the previous swings of the pendulum in the Western Desert since 1941 neither side had ever had the strength after achieving victory in an offensive battle to exploit it decisively: the losing side had always been able to withdraw and regroup closer to their main supply bases.
After six more weeks of building up their forces, Eighth Army was ready to strike. 220,000 men and 1,100 tanks under Montgomery made their move against the 115,000 men and 559 tanks of Panzer Armee Afrika.