History of the Italian Republic through a referendum. In April 1945, the Allies of World War II advanced in the Po plain supported by the Italian resistance movement, and defeated the fascist Italian Social Republic, a puppet state instituted by Nazi Germany and headed by Benito Mussolini. Mussolini was killed by resistance fighters in April 1945. Victor Emmanuel formally abdicated on 9 May 1946; his son became king as Umberto II of Italy. A Constitutional Referendum was held on 2 June 1946. Republicans won, and the monarchy was abolished. The Kingdom of Italy was no more. The House of Savoy, the Italian royal family, was
Umberto II of Italy limited to male-line descendants only. He was the first cousin of King Alexander I of Yugoslavia. He was accorded the title of Prince of Piedmont, which was formalised by Royal Decree on 29 September. Umberto was married in Rome on 8 January 1930 to Marie José of Belgium (1906–2001), daughter of King Albert I of the Belgians and his wife Queen Elisabeth, "née" Duchess Elisabeth in Bavaria. They had four children: As Prince of Piedmont, Umberto visited South America, between July and September 1924. With his preceptor, Bonaldi, he went to Brazil, Uruguay, Argentina and Chile. This trip was part