In early 1942, Darwin was used as a military base and as a transit point for forces and aircraft being sent to Timor, Ambon and Java in the Netherlands East Indies (modern Indonesia) before these islands fell to the Japanese.
The military garrison at Darwin was strengthened ahead of Japan's entry into the war. Northern Australia was considered vulnerable. Even before the war, the Army had raised a special Darwin Mobile Force to defend the north and then boosted defences with artillery batteries and other units. The Royal Australian Air Force (RAAF) sent squadrons north but had no fighters available to combat enemy aircraft. The Royal Australian Navy (RAN) established a shore base and a long-range wireless station, had vessels patrolling, and laid an anti-submarine boom across Darwin's outer harbour to obstruct enemy submarines.
On 19 February 1942, Darwin suffered its first and most devastating air raid. The Japanese had assessed that the base threatened the success of their operations against Timor and Java (they had captured Ambon already). Darwin's strategic importance was probably over-rated by the Japanese, but the 47 Allied naval and merchant ships in the harbour presented a desirable target nevertheless. The raid was intended to inflict considerable damage on the ships, township and military facilities.
Aircraft carriers in the Arafura Sea launched the first wave of aircraft to hit Darwin. The second wave took off later from Ambon. Area Combined Headquarters at Darwin disregarded early warnings of the impending attack from a Catholic missionary on Bathurst Island and a naval coastwatcher on Melville Island. Air raid alerts were not sounded until just before the first wave of aircraft appeared over Darwin. The pilots of several American fighters on patrol were taken by surprise, with most shot down. In and around the harbour, ships, wharves and parts of the town suffered great damage. Three Allied naval ships and five merchant ships were sunk and another ten ships were damaged. Most of the 280 or so people killed that day were victims of this first wave, mainly Allied service personnel, merchant seamen and wharf labourers ('wharfies') in and around Darwin harbour.
The first attack ended 42 minutes after it began. There was a lull of just over an hour before the second wave arrived. This time the military airfield was the main target. Six RAAF servicemen were killed and nine aircraft on the ground were destroyed. Most of the base's buildings were destroyed or damaged. Civilians in the township also died during the attacks, including several killed when the Post Office and a bomb shelter next to it received a direct hit.
Some troops and civilians showed great courage. The first two Military Medals for bravery in battle on Australian soil were awarded to anti-aircraft gunners for their actions on this day. Other servicemen and some civilians rescued crewmen from burning ships, many of whom were badly injured, while doctors and nurses treated many burnt and wounded survivors.
There was also an element of panic. Some civilians and servicemen 'went bush' or fled south, fearing the raid marked the start of an invasion. Most of those who deserted their posts and fled south were intercepted at Alice Springs but a handful actually reached southern cities. This panic and the true extent of the losses was hidden from the Australian public by strict censorship.
Darwin was subjected to a further 63 bombing raids, intermittently, until the last in November 1943. None were as devastating as this first one. The defences were strengthened and better organised, with American, Australian and British fighters, including Spitfires that had become famous in the Battle of Britain, deployed to defend the base.
Other areas of northern Australia also suffered attacks at various times. The next most devastating was on 3 March 1942 at Broome. Again without warning, Japanese aircraft swept in low, bombing and strafing Broome's harbour, township and airfield. Dozens of people were killed or wounded and 24 aircraft were destroyed. Many casualties were Dutch refugees from the Netherlands East Indies (modern Indonesia) whose flying boats were sitting defenceless on the harbour.
A small number of raids also occurred on the north-east coast of Australia. In late July 1942, Japanese flying boats based at Rabaul, New Britain, conducted three minor raids on Townsville, Queensland. Small numbers of bombs were dropped, falling wide of the target area, causing little or no damage. The last air raid on Australia was on 12 November 1943, when Darwin was attacked for the 64th and final time.