Digger is a military slang term for soldiers from Australia and New Zealand. Evidence of its use has been found in those countries as early as the 1850s, but its current usage in a military context did not become prominent until World War I, when Australian and New Zealand troops began using it on the Western Front around 1916–17. Evolving out of its usage during the war, the term has been linked to the concept of the Anzac legend, but within a wider social context, it is linked to the concept of "egalitarian mateship".
At the outbreak of World War I, Australia and New Zealand were both relatively "young" nations, with little exposure on the international stage. Deployed to Gallipoli in early 1915, the soldiers of both nations had a chance to prove themselves. Although the Gallipoli campaign resulted in heavy casualties and ultimately ended in withdrawal for the Allies, the campaign became strongly linked with the emergence of national identity in Australia and New Zealand. Through the manner in which the Australian and New Zealand soldiers endured the hardships of battle, the image that has become synonymous with the word "digger" has become linked with the concept of the Anzac legend, embodying the qualities of "endurance, courage, ingenuity, good humour, and […] mateship". In Australia, as the nation became more industrialised and urbanised, the term later assumed the qualities previous ascribed to the "bushman", including traits such as "hardiness, democratic spirit, mateship and resourcefulness".