Original: Mid 1800s During the 19th century large areas were successively separated to form the British colonies of Tasmania ( proclaimed as a separate colony named Van Diemen 's Land in 1825 ) , South Australia ( 1836 ) , Victoria ( 1851 ) and Queensland ( 1859 ) .
Simplified: During the 19th century large areas were separated to form the British colonies of Tasmania , South Australia , Victoria , Queensland and New Zealand .