Pope Leo XIII instituted this cross by the Apostolic Letter _Quod singulari Dei concessu_ of July 17, 1888,[40] to commemorate the fiftieth anniversary of his ordination to the priesthood. Originally it was intended to reward those persons who had distinguished themselves in organizing the Vatican exposition in which were exhibited the gifts which Leo had received from every part of the world on the occasion of his golden jubilee. Later, the bestowal was extended to those who were eminent in their devotion toward the Church and the Papacy. The cross was initially issued in three degrees, gold, silver and bronze; Pope St. Pius X in 1908 decreed that the cross should come only in gold. The four arms of the cross are decorated with a comet and in between the arms are found four lilies: these embellishments are meant to recall the coat of arms of the Pecci family from which Leo derived. In the center of the cross is placed a medal bearing the bust of the founding Pope with the inscription “Leo XIII, P.M. Ann. X” (the tenth year of Leo’s pontificate). The medal bears on the reverse side the tiara and the papal keys with the inscription “Pro Ecclesia et Pontifice.” On the reverse side of the arms of the cross are found these words “Prid. Cal. Ian. 1888.” The cross hangs from a red, white, and yellow ribbon, to be worn on the left chest. _Benemerenti_ This is the name of a series of medals issued by several Popes in order to reward distinguished services at special occasions. Pius VIII was the first to grant such a Benemerenti medal. The practice was continued by Gregory XVI in 1831 when he had a medal coined to reward those of his subjects who had shown themselves particularly faithful to the Pope during that troublesome year. Pope Pius IX did the same in gratitude to the soldiers who fought for him during the revolution of 1848 and 1849. St. Pius X, too, issued in 1910 a Benemerenti medal which was preferably granted for military services. A special medal is given to the Palatine guards after some years of faithful service. Pius XI created a Benemerenti medal to remunerate persons as well as groups who distinguished themselves in the organization of the Holy Year 1925 and of the missionary exhibition which was held in the Vatican in the same year. Besides these special medals there is a Benemerenti medal of a more general character. It comes in gold, silver and bronze and it bears the effigy and the name of the reigning Pope, and on the reverse side a crown of laurel and the letter “B” (“Benemerenti”). The medal hangs from a yellow ribbon edged with white, to be worn on the left chest.