A commonwealth comprising the continent of Australia, the island state of Tasmania, two external territories, and several dependencies. The first British settlement, a penal colony at Port Jackson (now part of Sydney), was established in 1788. The present-day states grew as separate colonies; six of them formed a federation in 1901. In 1911 Northern Territory joined the commonwealth and the Capital Territory, site of Canberra, was created. Canberra is the capital and Sydney is the largest city. Population: 20,400,000.