Australia was explored.
Australia ( [ əˈstreɪliə ] , [ ɒ - ] , [ - ljə ] ) , officially the Commonwealth of Australia , is a country comprising the mainland of the Australian continent , the island of Tasmania and numerous smaller islands . After the European discovery of the continent by Dutch explorers in 1606 , Australia 's eastern half was claimed by Great Britain in 1770 and initially settled through penal transportation to the colony of New South Wales from 26 January 1788 . The population grew steadily in subsequent decades , and by the 1850s most of the continent had been explored and an additional five self-governing crown colonies established .