Operation Compass (also ) was the first large British military operation of the Western Desert Campaign (1940–1943) during the Second World War. British, Empire and Commonwealth forces attacked Italian forces of the 10th Army (Marshal Rodolfo Graziani) in western Egypt and Cyrenaica, the eastern province of Libya, from December 1940 to February 1941.
The Western Desert Force (WDF) (Lieutenant-General Richard O'Connor) with about advanced from Mersa Matruh in Egypt on a five-day raid against the Italian positions of the 10th Army, which had about in fortified posts around Sidi Barrani in Egypt and in Cyrenaica. The WDF swiftly defeated the Italians in their fortified posts and at Sidi Barrani, then exploited their success, forcing the rest of the 10th Army out of Egypt and capturing the ports along the Libyan coast. The 10th Army was cut off as it retreated towards Tripolitania and defeated at the Battle of Beda Fomm, the remnants being pursued to El Agheila on the Gulf of Sirte.
The British took over and Libyan prisoners, hundreds of tanks, and more than and many aircraft, against WDF losses of killed and wounded, about of the infantry. The WDF was unable to continue beyond El Agheila, due to worn out vehicles and the diversion in March 1941 of the best-equipped units in Operation Lustre for the Battle of Greece. Italian reinforcements were rushed to Libya to defend Tripoli, assisted by the and .
Background
10th Army
When war was declared, the 5th Army (General Italo Gariboldi) was in Tripolitania the western Libyan province and the 10th Army (General Mario Berti) was in Cyrenaica to the east. Once the French in Tunisia no longer posed a threat to Tripolitania, units of the 5th Army were used to reinforce the 10th Army. When the Governor-General of Libya, Italo Balbo, was killed by friendly fire, Marshal Rodolfo Graziani took his place. Graziani expressed doubts about the ability of the large non-mechanised Italian force to defeat the British, who, though fewer in numbers, were motorised. After being reinforced from the 5th Army, the 10th Army controlled the equivalent of four corps with and tanks and . The XX Corps had the 60th Infantry Division "Sabratha" and the XXI Corps had the 1st CC.NN. Division "23 Marzo", the 2nd CC.NN. Division "28 Ottobre" and the 63rd Infantry Division "Cirene". XXII Corps had the 61st Infantry Division "Sirte" and XXIII Corps had the 4th CC.NN. Division "3 Gennaio" and the 64th Infantry Division "Catanzaro".
The new Libyan Divisions Group () had the part-motorised and lightly armoured Maletti Group (General Pietro Maletti), the 1st Libyan Division (Major-General Luigi Sibille) and the 2nd Libyan Division (Major-General Armando Pescatori). The Maletti Group had been formed at Derna on 8 July 1940 comprising seven Libyan motorised infantry battalions, a company of Fiat M11/39 tanks, a company of L3/33 tankettes, motorised artillery and supply units, as the main motorised unit of the 10th Army. On 29 August, as more tanks arrived from Italy, the (Libyan Tank Command [Colonel Valentini]) was formed with three groups: 1st Tank Group (Colonel Aresca) with the I Tank Battalion "M" and the XXI, LXI, and LXII Tank battalion "L", 2nd Tank Group (Colonel Antonio Trivioli), with the II Tank Battalion "M", less one company and the IX, XX, and LXI Tank Battalion "L"s and Maletti Group with one company from the LX Tank Battalion "L", one company from the II Tank Battalion "M", and three Libyan infantry battalions. became part of the (Royal Corps of Libyan Colonial Troops), with the 1st Libyan Division and the 2nd Libyan Division.
Western Desert Force
Middle East Command under General Archibald Wavell had about some outside Egypt, and . The RAF had composed of two squadrons of Hurricanes, one of Gloster Gladiators, three of Bristol Blenheims, three of Vickers Wellingtons and one of Bristol Bombays, about and The Western Desert Force (WDF) was commanded by Lieutenant-General Richard O'Connor with the 4th Indian Infantry Division (Major-General Noel Beresford-Peirse) and the 7th Armoured Division (Major-General Sir Michael O'Moore Creagh). From 14 December, troops of the 6th Australian Infantry Division (Major-General Iven Giffard Mackay), replaced the 4th Indian Division, which was sent to East Africa, less one brigade. The British had some fast Cruiser Mk I, Cruiser Mk II and Cruiser Mk III tanks with Ordnance QF 2-pounder guns, which were superior to Fiat M11/39 tanks. The British also had a battalion of Matilda II infantry tanks that while slow, were also equipped with the 2-pounder; the armour of the Matildas could not be penetrated by Italian anti-tank guns or field guns.