<P> The Australian Army first saw action in Operation Compass, the successful Commonwealth offensive in North Africa which took place between December 1940 and February 1941 . The 6th Division relieved the 4th Indian Division on 14 December . Although the 6th Division was not fully equipped, it had completed its training and was given the task of capturing Italian fortresses bypassed by the British 7th Armoured Division during its advance . </P> <P> The 6th Division went into action at Bardia on 3 January 1941 . Although a larger Italian force manned the fortress, with the support of British tanks and artillery the Australian infantry quickly penetrated the defensive lines . The majority of the Italian force surrendered on 5 January and the Australians took 40,000 prisoners . The 6th Division followed up this success by assaulting the fortress of Tobruk on 21 January . Tobruk was secured the next day, with 25,000 Italian prisoners taken . The 6th Division subsequently pushed west along the coast road to Cyrenaica and captured Benghazi on 4 February . The 6th Division withdrew for deployment to Greece later in February and was replaced by the untested 9th Division, which took up garrison duties in Cyrenaica . </P> <P> In the last week of March 1941, a German - led force launched an offensive in Cyrenaica which rapidly defeated the Allied forces in the area, forcing a general withdrawal towards Egypt (April 1941). The 9th Division formed the rear guard of this withdrawal, and on 6 April was ordered to defend the important port town of Tobruk for at least two months . During the ensuing siege of Tobruk the 9th Division, reinforced by the 18th Brigade of the 7th Division and British artillery and armoured regiments, used fortifications, aggressive patrolling and artillery to contain and defeat repeated German armoured and infantry attacks . The Mediterranean Fleet sustained Tobruk's defenders, and the elderly Australian destroyers made repeated supply "runs" into the port . Waterhen and Parramatta were sunk during these operations . Upon the request of the Australian Government, the bulk of the 9th Division was withdrawn from Tobruk in September and October 1941 and was replaced by the British 70th Division . The 2 / 13th Battalion was forced to remain at Tobruk until the siege was lifted in December when the convoy evacuating it was attacked, however . The defence of Tobruk cost the Australian units involved 3,009 casualties, including 832 killed and 941 taken prisoner . </P> <P> Two Australian fighter squadrons also took part in the fighting in North Africa . No. 239 Wing, a Curtiss P - 40 - equipped unit in the Desert Air Force, was dominated by Australians, in the form of two RAAF squadrons--No. 3 Squadron and No. 450 Squadron--and numerous individual Australians served in RAF squadrons . These two squadrons differed from the other RAAF squadrons in the Mediterranean in that they were made up of predominantly Australian ground - staff and pilots; the other RAAF units had ground crews made up of mostly British RAF personnel . </P>

In world war ii the islands near australia where a main battle was fought were the