Italy has been a unitary parliamentary republic since 2 June 1946, when the monarchy was abolished by a constitutional referendum. The President of Italy (''Presidente della Repubblica''), currently Sergio Mattarella since 2015, is Italy's head of state. The President is elected for a single seven years mandate by the Parliament of Italy and some regional voters in joint session. Italy has a written democratic constitution, resulting from the work of a Constituent Assembly formed by the representatives of all the anti-fascist forces that contributed to the defeat of Nazi and Fascist forces during the Civil War.