The Australian continent was first settled when ancestors of Indigenous Australians arrived via the islands of Maritime Southeast Asia and New Guinea over 50,000 years ago. European colonisation began in 1788 with the establishment of a British penal colony in New South Wales. Beginning in 1901, Australia maintained the White Australia policy for much of the 20th century, which forbade the entrance in Australia of people of non-European ethnic origins. Following World War II, the policy was gradually relaxed, and was abolished entirely by 1973. Since 1945, more than 7 million people have settled in Australia.