The First World War began when Britain and Germany went to war in August 1914, and Prime Minister Andrew Fisher's government pledged full support for Britain. The outbreak of war was greeted in Australia, as in many other places, with great enthusiasm.
Australia's early involvement in the Great War included the Australian Naval and Military Expeditionary Force landing at Rabaul on 11 September 1914 and taking possession of German New Guinea at Toma on 17 September 1914 and the neighbouring islands of the Bismarck Archipelago in October 1914. On 14 November 1914 the Royal Australian Navy made a significant contribution when HMAS Sydney destroyed the German raider SMS Emden.
On 25 April 1915 members of the Australian Imperial Force (AIF) landed at Gallipoli together with troops from New Zealand, Britain, and France. This began a campaign that ended with the evacuation of troops on 19 and 20 December 1915. Following Gallipoli, Australian forces fought campaigns on the Western Front and in the Middle East.
Throughout 1916 and 1917 losses on the Western Front were heavy and gains were small. In 1918 the Australians reached the peak of their fighting performance in the battle of Hamel on 4 July. From 8 August they then took part in a series of decisive advances until Germany surrendered on 11 November.
The Middle East campaign began in 1916 with Australian troops participating in the defence of the Suez Canal and the allied reconquest of the Sinai peninsula. In the following year Australian and other allied troops advanced into Palestine and captured Gaza and Jerusalem; by 1918 they had occupied Lebanon and Syria. On 30 October 1918 Turkey sued for peace.
For Australia, as for many nations, the First World War remains the most costly conflict in terms of deaths and casualties. From a population of fewer than five million, 416,809 men enlisted, of which over 60,000 were killed and 156,000 wounded, gassed, or taken prisoner.
The outbreak of war was greeted in Australia, as in many other places, with great public enthusiasm. In response to the overwhelming number of volunteers, the authorities set exacting physical standards for recruits. Yet, most of the men accepted into the army in August 1914 were sent first to Egypt, not Europe, to meet the threat which a new belligerent, the Ottoman Empire (Turkey), posed to British interests in the Middle East and the Suez Canal.
After four and a half months of training near Cairo, the Australians departed by ship for the Gallipoli peninsula, with troops from New Zealand, Britain, and France. The Australians landed at what became known as Anzac Cove on 25 April 1915 and established a tenuous foothold on the steep slopes above the beach. During the early days of the campaign, the allies tried to break through Turkish lines, while the Turks tried to drive the allied troops off the peninsula. Attempts on both sides ended in failure and the ensuing stalemate continued for the remainder of 1915. The most successful operation of the campaign was the evacuation of troops on 19 and 20 December, under cover of a comprehensive deception operation. As a result, the Turks were unable to inflict more than a very few casualties on the retreating forces.
After Gallipoli the AIF was reorganised and expanded from two to five infantry divisions, all of which were progressively transferred to France, beginning in March 1916. The AIF mounted division that had served as additional infantry during the campaign remained in the Middle East. When the other AIF divisions arrived in France, the war on the Western Front had long been settled in a stalemate, with the opposing armies facing each other from trench systems that extended across Belgium and north-east France, from the English Channel to the Swiss border. The development of machine-guns and artillery favoured defence over attack and compounded the impasse, which lasted until the final months of the war.
While the overall hostile stasis continued throughout 1916 and 1917, the Australians and other allied armies repeatedly attacked, preceded by massive artillery bombardments intended to cut barbed wire and destroy enemy defences. After these bombardments, waves of attacking infantry emerged from the trenches into no man's land and advanced towards enemy positions. The surviving Germans, protected by deep and heavily reinforced bunkers, were usually able to repel the attackers with machine-gun fire and artillery support from the rear. These attacks often resulted in limited territorial gains followed, in turn, by German counter-attacks. Although this style of warfare favoured the defence, both sides sustained heavy losses.
In July 1916 Australian infantry were introduced to this type of combat at Fromelles, where they suffered 5,533 casualties in 24 hours. By the end of the year about 40,000 Australians had been killed or wounded on the Western Front. In 1917 a further 76,836 Australians became casualties in battles, such Bullecourt, Messines, and the four-month campaign around Ypres, known as the battle of Passchendaele.
In March 1918 the German army launched its final offensive of the war, hoping for a decisive victory before the military and industrial strength of the United States could be fully mobilised in support of the allies. The Germans initially met with great success, advancing 64 kilometres past the region of the 1916 Somme battles, before the offensive lost momentum. Between April and November the stalemate of the preceding years began to give way, as the allies combined infantry, artillery, tanks, and aircraft more effectively, demonstrated in the Australian capture of Hamel spur on 4 July 1918. The allied offensive, beginning on 8 August at Amiens, also contributed to Australian successes at Mont St Quentin and Péronne and to the capture of the Hindenburg Line. In early October the Australian divisions withdrew from the front for rest and refitting; they were preparing to return when Germany surrendered on 11 November.
Unlike their counterparts in France and Belgium, the Australians in the Middle East fought a mobile war against the Ottoman Empire in conditions completely different from the mud and stagnation of the Western Front. The light horsemen and their mounts had to survive extreme heat, harsh terrain, and water shortages. Nevertheless, casualties were comparatively light, with 1,394 Australians killed or wounded in three years of war. This campaign began in 1916 with Australian troops participating in the defence of the Suez Canal and the allied reconquest of the Sinai peninsula. In the following year Australian and other allied troops advanced into Palestine and captured Gaza and Jerusalem; by 1918 they had occupied Lebanon and Syria. On 30 October 1918 Turkey sued for peace.
Australians also served at sea and in the newly formed flying corps. The Royal Australian Navy (RAN), under the command of the Royal Navy, made a significant contribution early in the war, when HMAS Sydney destroyed the German raider Emden near the Cocos Islands in November 1914. The Great War was the first armed conflict in which aircraft were used; about 3,000 Australian airmen served in the Middle East and France with the Australian Flying Corps, mainly in observation capacities or providing infantry support.