King William IV signs Letters Patent establishing the province of South Australia.

William IV was King of the United Kingdom of Great Britain and Ireland and King of Hanover from 26 June 1830 until his death in 1837. The third son of George III, William succeeded his elder brother George IV, becoming the last king and penultimate monarch of Britain's House of Hanover.

South Australia is a state in the southern central part of Australia. With a total land area of 984,321 square kilometres (380,048 sq mi), it is the fourth-largest of Australia's states and territories by area, which includes some of the most arid parts of the continent, and with 1.8 million people, it is the fifth-largest of the states and territories by population. This population is the second-most highly centralised in the nation after Western Australia, with more than 77% of South Australians living in the capital Adelaide or its environs. Other population centres in the state are relatively small; Mount Gambier, the second-largest centre, has a population of 26,878.

February 19 is the 50th day of the year in the Gregorian calendar; 315 days remain until the end of the year.