On 5 April 1941 German troops invaded Greece and Yugoslavia. Yugoslavia was overrun in a matter of days while the Greek campaign lasted just over three weeks. A British guarantee to support Greece if it was attacked had already been invoked when the Italians invaded in October 1940. Assistance on this occasion was minimal, but the Italians were defeated when the Greeks repelled their attempt to invade through Albania.

In 1941 the defence of Greece was placed largely in the hands of troops from Australia and New Zealand. During the course of the campaign this dominion force, although it included a British brigade, became known as the ANZAC Corps. Even before the German invasion, senior British military and political figures doubted the wisdom of attempting to fight the Germans in Greece and some were already discussing evacuation plans. Lacking aircraft and armour, the Allies were poorly prepared to withstand the German onslaught which came in the form of ten infantry, armoured and specialist mountain warfare divisions. Outnumbered on the ground and in the air the British Commonwealth force was unable to deploy sufficient troops in any one area to halt the German advance. Instead they found themselves conducting a series of withdrawals, slowing the Germans down and offering brave and sometimes successful local resistance.

The campaign was dogged by poor liaison between the ANZACs and their Greek allies - problems which were exacerbated by language difficulties and a lack of equipment. While the ANZAC force never lost its cohesion they were never in a position to reverse German successes. By 20 April, when it was clear that they could do no more than disrupt and slow the German advance, the Greek Government agreed that the force should be evacuated.

The final withdrawal to the evacuation beaches on the Peloponnese was skilfully conducted and the evacuation began on 24 April. Over the next five nights more than 50,000 troops left Greece. They left behind 320 dead Australians - a further 2,065 became prisoners of war. More than 290 New Zealanders were killed and over 1,600 captured. Hundreds of others were cut off during the fighting, many of these men made their way back to Allied lines in Crete or North Africa via Turkey or the Greek islands.