FERT

FERT is the motto of the royal House of Savoy and Kingdom of Italy. The motto was adopted by Duke Vittorio Amedeo II.
It appeared for the first time on the collar of the Supreme Order of the Most Holy Annunciation, or Ordine Supremo della Santissima Annunziata, the primary dynastic order of the kingdom.
The meaning of the letters has been a matter of some controversy, to which a number of interpretations have been offered. The motto is believed to be an acronym of:

Foedere et Religione Tenemur ;
Fortitudo Eius Rhodum Tenuit, referring to the victory of Amadeus V, Count of Savoy, who fought in the 1315 siege of Rhodes; or either
Fortitudo Eius Rempublicam Tenet ; or
Fides Est Regni Tutela.