It was established on I April 1800 by Ferdinand IV King of Naples and Sicily to award those who did important favors and gave an extraordinary proof of loyalty to the Head of the Royal House and to the Royal Family.

In 1810 the King reformed its Statutes.
The Order is divided into three Ranks: Knights of Grand Cross, with fess, cross and plate; Knights Commanders, with neck ribbon and cross; Knights, with ribbon and cross to the buttons.

There are also those Decorated with golden and silver medal.

The decoration is formed by a golden round shield bearing the image of St. Ferdinand, edged by a blue-enameled round plate with the inscription "FIDEI ET MERITO", bordered by six golden rays edged by six white enameled lilies. The Royal Crown tops it.
On the verso, in the middle of the round shield, there is the inscription "FERD. IV. INST: ANNO 1800".

The ribbon is blue and edged in dark red.

The present Grand Master is HRH Prince Charles of Bourbon Two Sicilies, Duke of Castro.


Other Orders:
- Illustrious Royal Order of San Gennaro
- Sacred Military Constantinian Order of St. George
- Royal Military Order of St. George and Reunion
- Royal Order of Francis I