On 1 January 1852 the Papal States introduced postage stamps. Postal service in the Papal States was given the highest priority and was conducted with the greatest efficiency. Postal operations were subject to the Cardinal Camerlengo of the Holy Roman Church, who issued legislation concerning the service though decrees and also determined the postal fees. Pope Pius IX, who ruled at a time in which the temporal power of the papacy was hotly debated, did not want his effigy to be affixed to postage stamps; rather, he wanted the symbol of papal power to be displayed: the image of the keys crossed over the papal tiara. For this reason the earliest series of postage stamps for the Papal States are perhaps a bit monotonous in design, even though some variety occurs in the design of the cornices. The first stamp was produced by the printing press of the Apostolic Camera and consisted of four sheets, each bearing 25 stamps. A second series, with the stamps valued in cents, was issued following a monetary reform in 1867. The third series, similar to the second, appeared in the following year. This time, however, each stamp had a serrated border and was printed on tracing paper that was colored on the facing side and white on the back.
With the advent of several national postal systems, international postal regulation was urgently required. In 1874 the General Postal Union was created with the adhesion of 21 signatory states (including almost all of Europe, Turkey and the United States), which formed “a single territory” for the purpose of postal regulation. The Union made possible the introduction of fixed regulations and uniform fees for all the member nations, without regard for the nature of the journey required or the means used to carry the post. Success was once again immediate. So many nations requested admission that already in 1878 the name of the Union was changed to the Universal Postal Union. The revolutionary advent of the postcard in 1870 did away with the secrecy of the letter in exchange for a reduced postage fee. The early nineteenth century saw the introduction of illustrated postcards, the success of which was guaranteed by the possibility of printing them with additional colors.
Article Two of the Lateran Treaty of 2 June 1929 assures that Italy recognizes “the sovereignty of the Holy See in international matters as an inherent attribute in conformity with its traditions and the requirements of its mission to the world.” As a consequence, the rights of the new State were recognized in every regard, including the right to its own postal service. Vatican City State was admitted to the U.P.U. on 1 June 1929, while the Italian government provided personnel and material. On 29 July 1929 Vatican City State and the Italian State signed a bilateral agreement providing for the operation of postal services in accord with the Stockholm treaties of 28 August 1924, the Fundamental Law of the Vatican State and the law concerning the sources of law, which were promulgated by papal decree, respectively as n. 1 and n. 2, on 7 June 1929. The Vatican Postal Service was formally inaugurated by Ordinance VIII on 30 July 1929, and began operation on 1 August 1929.
Newly issued series of Vatican postage stamps are authorized by “Ordinances” which are published in the Acta Apostolicae Sedis, a type of official publication of the Holy See. Stamp collectors and philatelic specialists throughout the world are particularly interested in ordinances and Acts concerning first day-of-issue stamps. Later the Vatican began releasing in the same way new series of postal stationery, including postcards and aerograms.