Umberto's reign lasted for 34 days, from 9 May until his formal deposition on 12 June , although he had been the de facto head of state since Due to his short reign, he was nicknamed the May King Italian : Re di maggio. As heir apparent to the throne, he received a customary military education and pursued a military career afterwards. In , he commanded an army group during the brief Italian invasion of France shortly before the French capitulation.
In , he was promoted to Marshal of Italy but was otherwise inactive as an army commander during much of the Second World War. Umberto turned against the war following Italian defeats at Stalingrad and El Alamein , and tacitly supported the ouster of Benito Mussolini. In , Victor Emmanuel, compromised by his association with Italian fascism and desperate to repair the monarchy's image, transferred most of his powers to Umberto.
He transferred his remaining powers to Umberto later in and named him Lieutenant General Luogotenente of the Realm; while retaining the title of King. As the country prepared for the Italian institutional referendum on the continuation of the Italian monarchy , Victor Emmanuel abdicated his throne in favour of Umberto, in the hope that his exit might bolster the monarchy.
The June referendum saw voters voting to abolish the monarchy, and Italy was declared a republic days later. Umberto departed the country; he and other male members of the House of Savoy were barred from returning.
He lived out the rest of his life in exile in Cascais , on the Portuguese Riviera. He died in Geneva Cantonal Hospital in Umberto was born at the Castle of Racconigi in Piedmont. As such, he was heir apparent from birth since the Italian throne was limited to male descendants. He was accorded the title Prince of Piedmont , which the Royal Decree formalised on 29 September During the crisis of May , when Victor Emmanuel III decided to break the terms of the Triple Alliance by declaring war on the Austro-Hungarian Empire , he found himself in a quandary as the Italian Parliament was against declaring war; several times, the king discussed abdication, with the throne to pass to the 2nd Duke of Aosta instead of Umberto.
