Thaon di Revel was born in Turin from a family of the Savoyard and Niçard nobility of Scottish descent, a minor son of Marquess and Count Ottavio Thaon di Revel. He took part as Rear-admiral in the Italo-Turkish War, commanding Italian cruisers in the Battle of Beirut. He twice served as Naval Chief of Staff during World War I and was reluctant to risk the Italian battlefleet in anything other than a major surface action. He favoured the action of smaller vessels, as the MAS which sunk the Austrian battleship Szent István. After the Italian rout at Caporetto he secured the coastal area. In the late days of the war he led the bombardment of Durazzo and the quick occupation of the coasts of Istria and Dalmatia.