For at least 40,000 years[13] before the first British settlement in the late 18th century,[14][15] Australia was inhabited by indigenous Australians,[16] who spoke languages grouped into roughly 250 language groups.[17][18] 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; the continent was explored and an additional five self-governing crown colonies were established.