Official History of Australia in the War of 1914–1918

Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. Australia is the largest country by area in Oceania and the world's sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a megadiverse country, and its size gives it a wide variety of landscapes and climates, with deserts in the centre, tropical rainforests in the north-east, and mountain ranges in the south-east.

World War I or the First World War, often abbreviated as WWI, was one of the deadliest global conflicts in history. It was fought between two coalitions, the Allies and the Central Powers. Fighting occurred throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died as a result of genocide, while the 1918 Spanish flu pandemic was exacerbated by the movement of combatants during the war.

Charles Edwin Woodrow Bean, usually identified as C. E. W. Bean, was Australia's official war correspondent, subsequently its official war historian, who wrote six volumes and edited the remaining six of the twelve-volume Official History of Australia in the War of 1914–1918. He was the foundational force and primary advocate in establishing the Australian War Memorial (AWM). According to the Online International Encyclopedia of the First World War, no other Australian has been more influential in shaping the way the First World War is remembered and commemorated in Australia.

The First Australian Imperial Force was the main expeditionary force of the Australian Army during the First World War. It was formed as the Australian Imperial Force (AIF) following Britain's declaration of war on Germany on 15 August 1914, with an initial strength of one infantry division and one light horse brigade. The infantry division subsequently fought at Gallipoli between April and December 1915, with a newly raised second division, as well as three light horse brigades, reinforcing the committed units.

The Australian Naval and Military Expeditionary Force (AN&MEF) was a small volunteer force of approximately 2,000 men, raised in Australia shortly after the outbreak of World War I to seize and destroy German wireless stations in German New Guinea in the south-west Pacific. The German wireless installations were ordered to be destroyed because they were used by Vizeadmiral Maximilian von Spee's East Asia Squadron of the Imperial German Navy, which threatened merchant shipping in the region. Following the capture of German possessions in the region, the AN&MEF provided occupation forces for the duration of the war. New Zealand provided a similar force for the occupation of German Samoa.

Rabaul is a township in the East New Britain province of Papua New Guinea, on the island of New Britain. It lies about 600 kilometres to the east of the island of New Guinea. Rabaul was the provincial capital and most important settlement in the province until it was destroyed in 1994 by falling ash from a volcanic eruption in its harbour. During the eruption, ash was sent thousands of metres into the air, and the subsequent rain of ash caused 80% of the buildings in Rabaul to collapse. After the eruption the capital was moved to Kokopo, about 20 kilometres (12 mi) away. Rabaul is continually threatened by volcanic activity, because it is on the edge of the Rabaul caldera, a flooded caldera of a large pyroclastic shield.

The Royal Australian Navy (RAN) is the naval force of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (CN) Vice Admiral Mark Hammond AM, RAN. CN is also jointly responsible to the Minister of Defence (MINDEF) and the Chief of Defence Force (CDF). The Department of Defence as part of the Australian Public Service administers the ADF.

The Australian Flying Corps (AFC) was the branch of the Australian Army responsible for operating aircraft during World War I, and the forerunner of the Royal Australian Air Force (RAAF). The AFC was established in 1912, though it was not until 1914 that it began flight training.

Home front is an English language term with analogues in other languages. It is commonly used to describe the full participation of the British public in World War I who suffered Zeppelin raids and endured food rations as part of what came to be called the "Home Front".

The Battle of the Somme, also known as the Somme offensive, was a battle of the First World War fought by the armies of the British Empire and the French Third Republic against the German Empire. It took place between 1 July and 18 November 1916 on both sides of the upper reaches of the river Somme in France. The battle was intended to hasten a victory for the Allies. More than three million men fought in the battle, of whom one million were either wounded or killed, making it one of the deadliest battles in all of human history.

The Western Front was one of the main theatres of war during the First World War. Following the outbreak of war in August 1914, the German Army opened the Western Front by invading Luxembourg and Belgium, then gaining military control of important industrial regions in France. The German advance was halted with the Battle of the Marne. Following the Race to the Sea, both sides dug in along a meandering line of fortified trenches, stretching from the North Sea to the Swiss frontier with France, which changed little except during early 1917 and in 1918.