Luogotenente

The Italian word luogotenente (English: lieutenant), plural luogotenenti, is an etymological parallel to lieutenant, deriving from the Latin locum tenens "holding a place", i.e. someone who fills a position instead of another, as a substitute, deputy, et cetera.

It has a few specific historical uses:

The knightly officer who is in daily command of the Grand Master's own regimental company, to which the famigliari (closest personal staff) belonged.

It was also the governor (elsewhere other titles, such as provveditore, were used) for the Venetian Republic on the island of Cyprus, which it bought from its last crusader king from the house of Lusignan, usually for a two-year term, until the Turks overran it in 1570. Besides him the military command was entrusted to a capitano ('captain', de facto military governor), from 1480 to 1571 (when Famagusta, the last fortress, fell). Thereafter the island became a Sandjak (military province) of the Ottoman Empire (Kibris in Turkish), part of the Eyalet of the Islands (ruled from Rhodes island), governed by an Ottoman Muhassil (Lieutenant-governor; already appointed on paper, for the conquest, since 1690), since 1745 by a (higher rank, equally military) vali.

In the Neapolitan Two Sicilies Kingdom there was a Luogotenente generale dei reali domini al di là del Faro meaning Lieutenant-general of the royal domains beyond the Lighthouse, i.e. the Governor appointed by the King for Sicily (Statute of 11 December 1816).

In the Savoy dynasty's Kingdom of Piedmont-Sardinia and later united Kingdom of Italy, when the King was away from his office for some reason (e.g. to follow the war on the battlefield) he could appoint a Luogotenente Generale del Regno (Lieutenant-general of the realm) (chosen from members of royal family) to carry out some of the King's duties as a Viceroy.

It happened on 1848, when the king Carlo Alberto reached the battlefield in Lombardia, Eugenio Savoia-Carignano was 'Luogotenente Generale del Regno' and was up to him to announce next year that the defeated king abdicated and succession passed to the son Vittorio Emanuele II. Eugenio Savoia-Carignano covered again the same role in 1859 and in 1866 when Vittorio Emanuele II was involved in the second and third War of Independence. Finally in 1860/1861 he was appointed Luogotenential duties but limited to Toscana and to southern Italy, when those regions passed under Kingdom of Sardinia.

...
Wikipedia