The Western Desert Campaign (Desert War), took place in the deserts of Egypt and Libya and was the main theatre in the North African Campaign during the Second World War. The campaign began in September 1940 with the Italian invasion of Egypt; Operation Compass, a British five-day raid in December 1940, led to the destruction of the Italian 10th Army. Benito Mussolini sought help from Adolf Hitler, who responded with a small German force sent to Tripoli under Directive 22 (11 January). The German Afrika Korps (Generalleutnant Erwin Rommel) was under nominal Italian command but Italian dependency on Nazi Germany made it the dominant partner.
In the spring of 1941, Axis forces under Rommel pushed the British back to Egypt except for the port of Tobruk, where the Siege of Tobruk took place until it was relieved during Operation Crusader. The Axis forces were forced to retire to where they had started by the end of the year. In 1942 Axis forces drove the British back again and captured Tobruk after the Battle of Gazala but failed to gain a decisive victory. On the final Axis push to Egypt, the British retreated to El Alamein, where at the Second Battle of El Alamein the Eighth Army defeated the Axis forces. They were driven out of Libya to Tunisia, where they were defeated in the Tunisian Campaign.
For Hitler the Eastern Front against the Soviet Union dwarfed the desert war, which was a holding action of secondary importance. The Axis never had sufficient resources or the means to deliver them, to defeat the British. The British missed several opportunities to finish the campaign when they diverted resources to Greece and the Levant in 1941 and the Far East in 1942.
Cyrenaica (Libya) had been an Italian colony since the Italo-Turkish War (1911–1912). With Tunisia, a part of French North Africa to the west and Egypt to the east, the Italians prepared to defend both frontiers through a North Africa Supreme Headquarters, under the command of the Governor-General of Italian Libya, Marshal of the Air Force, Italo Balbo. Supreme Headquarters had the 5th Army (General Italo Gariboldi) and the 10th Army (General Mario Berti) which in mid-1940 had nine metropolitan divisions of about 13,000 men each, three Blackshirt and two Libyan divisions with 8,000 men each. Italian army divisions had been reorganised in the late 1930s, from three regiments each to two and reservists were recalled in 1939, along with the usual call-up of conscripts.
Morale was considered to be high and the army had recent experience of military operations. The Italian navy had prospered under the Fascist regime, which had paid for fast, well-built and well-armed ships and a large submarine fleet but the navy lacked experience and training. The air force had been ready for war in 1936 but had stagnated by 1939 and was not considered by the British to be capable of maintaining a high rate of operations. The 5th Army with eight divisions was based in Tripolitania, the western half of Libya opposite Tunisia and the 10th Army with six infantry divisions, held Cyrenaica in the east. When war was declared, the 10th Army deployed the 1st Libyan Division Sibelle on the frontier from Giarabub to Sidi Omar and XXI Corps from Sidi Omar to the coast, Bardia and Tobruk. The XXII Corps moved south-west of Tobruk, to act as a counter-attack force.