1946, june, Milano, ITALY : The Proclamation of ITALIAN REPUBLIC. Italy became a republic after a referendum held on 2 June 1946, a day celebrated since as Republic Day. This was also the first time that Italian women were entitled to vote. Victor Emmanuel III's son, Umberto II, was forced to abdicate and exiled. The Republican Constitution was approved on 1 January 1948. Under the Treaty of Peace with Italy of 1947, most of Venezia Giulia was lost to Yugoslavia and, later, the Free Territory of Trieste was divided between the two states. Italy also lost all its colonial possessions, formally ending the Italian Empire