[4] The order was founded by Cosimo I de' Medici,[5] first Grand Duke of Tuscany, with the approbation of Pope Pius IV on 1 October 1561.

[8] The Turks and the pirates were making dangerous inroads on the coast of the Tyrrhenian Sea where Cosimo had recently inaugurated the new port of Livorno.

Cosimo also needed a symbolic fight to unite the nobility of the different cities that combined to form his new grand duchy (including Florence and Siena), and to demonstrate his support of the Roman Catholic Church.

In its early years, the Order took part successfully in the Spanish wars against the Ottomans, being present at the siege of Malta (1565), the Battle of Lepanto (1571) and the 1607 capture of Annaba in Algeria by the then admiral Jacopo Inghirami.

In particular, the Knights made some incursions into the Aegean Islands controlled by the Turks, and took part in the campaigns in Dalmatia, Negroponte and Corfu.

The Order concentrated on the coastal defence and on ordnance duties, but did not avoid the chance to send help to the Republic of Venice, then engaged in a desperate war against the Ottoman Empire.

Grand Duke Peter Leopold of Tuscany promoted a reorganization of the order, turning it into an institute for education of the Tuscan nobility.

[1] An attempt was made to suppress it during the Napoleonic era, on 9 April 1809, but Ferdinand III of Lorraine restored it on 22 December 1817, with some changes to the statutes.

[15] To join the Order a postulant had to be at least eighteen years of age, able to meet the financial obligations of membership, make the necessary noble proofs and not be descended from heretics.