The siege of Tobruk lasted for 241 days in 1941, after Axis forces advanced through Cyrenaica from El Agheila in Operation Sonnenblume against Allied forces in Libya, during the Western Desert Campaign (1940–1943) of the Second World War. In late 1940, the Allies had defeated the Italian 10th Army during Operation Compass and trapped the remnants at Beda Fomm. During early 1941, much of the Western Desert Force (WDF) was sent to the Greek and Syrian campaigns. As German troops and Italian reinforcements reached Libya, only a skeleton Allied force remained, short of equipment and supplies. The defenders quickly became known as the Rats of Tobruk. Operation Sonnenblume forced the Allies into a retreat to the Egyptian border. A garrison, consisting mostly of the 9th Australian Division (Lieutenant-General Leslie Morshead) remained at Tobruk, to deny the port to the Axis, while the WDF reorganised and prepared a counter-offensive. The Axis siege of Tobruk began on 10 April, when the port was attacked by a force under Generalleutnant Erwin Rommel and continued during three relief attempts, Operation Brevity Operation Battleaxe and Operation Crusader The occupation of Tobruk deprived the Axis of a supply port closer to the Egypt–Libya border than Benghazi, west of the Egyptian frontier, which was within the range of RAF bombers; Tripoli was to the west in Tripolitania. The siege diverted Axis troops from the frontier and the Tobruk garrison repulsed several Axis attacks. The port was frequently bombarded by artillery, dive-bombers and medium bombers, as the RAF flew defensive sorties from airfields far away in Egypt. Allied naval forces, such as the British Mediterranean Fleet (including the Inshore Squadron) ran the blockade, carrying reinforcements and supplies in and wounded and prisoners out. On 27 November, Tobruk was relieved by the Eighth Army (which controlled British and other Allied ground forces in the Western Desert from September 1941) in Operation Crusader. Background Terrain The Western Desert Campaign was fought from Mersa Matruh in Egypt to Gazala in Cyrenaica on the Libyan coast, an area about wide along Via Balbia along the coast, the only paved road. A sand sea inland marked the southern limit of the desert, which was at its widest at Giarabub and Siwa; in British parlance, the Western Desert came to include eastern Cyrenaica in Libya. Extending inland from the coast lies a raised, flat plain of stony desert, about above sea level, for to