The Order of Pius is the third in rank of the Pontifical Orders of Knighthood. It was erected by Pope Pius IX by the Brief _Romanis Pontificibus_, and was called after the founder, but also to honor the memory of Pius IV (1559-65) who in 1559 had instituted an Ordo Pianus. Since the latter had ceased to exist in the course of time, the order established by Pius IX could not be considered a continuation of it. However, the Pope stated specifically that he wished to “revive the ancient appellation introduced by his predecessor.” The order consisted of two degrees: knights of the first and knights of the second class. At the moment of nomination, they received title to personal nobility; in the case of the knights of the first class, the title was transmissible to their sons. The decoration of the order is an eight-pointed blue star surrounding a medal with the inscription “Pius IX” and “Virtuti et Merito”; the reverse bears the date of the foundation of the order, 1847. The decoration hangs from a blue ribbon with red edgings. The uniform is blue. The knights of the second degree were to wear the emblem on the left chest, those of the first degree had the privilege to wear it hanging from a blue ribbon around the neck. The latter could also wear a silver emblem similar to the badge but of larger dimensions on the left chest; only, however, after obtaining the special and expressed authorization of the Holy See. Several of the stipulations made by Pius IX were changed within the next hundred years. One might speak of these changes as the story of the _minutiae_ of an order of knighthood. In the first place there was the plaque. Two years after the founding of his order, Pius IX issued at Gaeta, in exile, the Brief _Cum hominum mentes_ (June 17, 1849), wherein he ordered that from that date on all knights of the first class enjoyed the privilege of the emblem, but that a special permission of the Holy See was needed to wear a jewelled emblem. Moreover, knights of the first class should no longer wear the star of the order pendent from a collar around the neck, but from the grand cordon. This rule made them Knights of the Grand Cross. By the Brief _In ipso_ of Nov. 11, 1856, issued from the palace of the Quirinal, Pope Pius IX extended the number of degrees to three: (1) Knights of the Grand Cross, wearing the grand cordon emblem; (2) Knights of the Second Class or Commanders, wearing the collar; (3) Knights of the Third Class, wearing the emblem on a small ribbon on the chest. Pope Pius X in his Brief _Multum ad excitandos_ reintroduced the famous emblem and instituted an intermediary degree by dividing the commanders into two classes: those with the emblem and those without.