The development of a New Zealand identity and national character, separate from the British colonial identity, is most often linked with the period surrounding the First World War, which gave rise to the concept of the Anzac spirit. However, cultural links between New Zealand and Great Britain are maintained by a common language, sustained immigration from the UK, and the fact that many young New Zealanders spend time in Britain on "overseas experience", known as "OE". New Zealanders also identify closely with Australians, as a result of the two nations' shared historical, cultural and geographic characteristics.