The Medici Grand Ducal House of Tuscany bears its titles as a result of the Papal Bull on 27 August 1569 by Pope Pius V to Cosimo I and to all his firstborn male heirs, or closest male relative of the Medici family in perpetuity, in the event of extinction of the firstborn branch of Cosimo I.
Upon the extinction of the Grand Ducal branch, H.E.H. Anna Maria Luisa de’ Medici, Grand Princess of Tuscany, decreed the Medici Ottajano line, direct descendants of Lorenzo “The Magnificent”, as successors.
Therein, in 2001, HRH Ottaviano de’ Medici, Grand Duke of Tuscany, assumed his title per the decree by the Pope Pius V and per the dynastic rules of the family made in 1737 by the Grand Princess of Tuscany Anna Maria Luisa de’ Medici, which still requires the Grand Duke to live in Florence.