The younger brother, who became king, of the princess that SS Principessa Mafalda was not named after, reigned for 34 days.
Princess Mafalda of Savoy (2 November 1902  27 August 1944) was the second daughter of King Victor Emmanuel III of Italy and his wife Elena of Montenegro. 
 The future King Umberto II of Italy was her younger brother. 
Umberto II (Italian: "Umberto Nicola Tommaso Giovanni Maria di Savoia" ; 15 September 190418 March 1983), was the last King of Italy. 
 He reigned for 34 days, from 9 May 1946 to 12 June 1946, although he had been "de facto" head of state since 1944, and was nicknamed the May King (Italian: Re di Maggio ). 
 Named after Princess Mafalda of Savoy, second daughter of King Victor Emmanuel III, the ship entered NGI's South American service between Genoa and Buenos Aires in 1909. 
