New South Wales is a state on the east coast of Australia. It borders Queensland to the north, Victoria to the south, and South Australia to the west. Its coast borders the Tasman Sea to the east. The Australian Capital Territory is an enclave within the state. New South Wales' state capital is Sydney, which is also Australia's most populous city. In December 2018, the population of New South Wales was over 8 million, making it Australia's most populous state. Just under two-thirds of the state's population, 5.1 million, live in the Greater Sydney area. Inhabitants of New South Wales are referred to as New South Welshmen.
The Colony of New South Wales was founded as a penal colony in 1788. It originally comprised more than half of the Australian mainland with its western boundary set at 129th meridian east in 1825. The colony also included the island territories of New Zealand, Van Diemen's Land, Lord Howe Island, and Norfolk Island. During the 19th century, most of the colony's area was detached to form separate British colonies that eventually became New Zealand and the various states and territories of Australia. However, the Swan River Colony has never been administered as part of New South Wales.
Lord Howe Island remains part of New South Wales, while Norfolk Island has become a federal territory, as have the areas now known as the Australian Capital Territory and the Jervis Bay Territory.