Irish Australians () are an ethnic group of Australian citizens of Irish descent, which include immigrants from and descendants whose ancestry originates from the island of Ireland. Irish Australians have played a considerable role in the history of Australia. They came to Australia from the late eighteenth century as convicts and free settlers wanting to immigrate from their homeland. Some of those who were transported to Australia were prisoners of war, many of whom had fought in the 1798 Irish rebellion for independence, whereas others were settlers who struggled to establish their lives during the Irish famine and the harsh years in Ireland that followed. They made substantial contributions to Australia's development in many different areas. In the late 19th century, Irish Australians constituted up to a third of the country's population. There is no definitive figure of the total number of Australians with an Irish background. At the 2011 Australian census, 2,087,800 residents identified themselves as having Irish ancestry either alone or in combination with another ancestry. This nominated ancestry was third behind English and Australian in terms of the largest number of responses and represents 10.4% of the total population of Australia. However this figure does not include Australians with an Irish background who chose to nominate themselves as 'Australian' or other ancestries. The Australian embassy in Dublin states that up to 30% of the population claim some degree of Irish ancestry. History Demographic history Around 40,000 Irish convicts were transported to Australia between 1791 and 1867, including at least 325 who had participated in either the Irish Rebellion of 1798, the rebellion of 1803 or the Young Ireland skirmishes in 1848. Once in Australia, some were involved in the 1804 Castle Hill convict rebellion. Continual tension on Norfolk Island in the same year also led to an Irish revolt. Both risings were soon crushed. As late as the 1860s Fenian prisoners were being transported, particularly to Western Australia, where the Catalpa rescue of Irish radicals off Rockingham was a memorable episode. Other than convicts, most of the laborers who voluntarily emigrated to Australia in the 19th century were drawn from the poorest sector of British and Irish society. After 1831, the Australian colonies employed a system of government assistance in which all or most immigration costs were paid for chosen immigrants, and the colonial authorities used these schemes to exercise some control over immigration. While these assisted