The order was founded by Cosimo I de' Medici, first Grand Duke of Tuscany, with the approbation of Pope Pius IV on 1 October 1561. The rule chosen was that of the Benedictine Order.
The order was established by Cosimo I de' Medici, first Grand Duke of Tuscany, with the approval of Pope Pius IV on 1 October 1561. This aligns with the practice of adopting a rule from the Benedictine Order.