The Republic of Iceland was established on 17 June 1944, when Iceland became a republic and the office of president replaced the monarch as head of state. The date was chosen to coincide with the birthday of Jón Sigurðsson, a leading symbol of Iceland's independence movement.
The founding of the republic was a major constitutional milestone. It is closely associated with Þingvellir, where the republic was formally proclaimed, and with the history of Althing.