On June 9, 1952, Vatican City issued a 50-lire stamp commemorating the centenary of the first Roman States postage stamp. At the same time, Vatican City also issued a souvenir sheet on cream (or ivory) paper of four identical commemorative stamps. The sheet also contained the triple papal tiara and Crossed Keys with the Italian description, "Centanario del 1° Francobollo dello Stato Pontificio, 1852-1952." (Centenary of the first Papal States Postage Stamp).
The roots of the Roman States (the medieval Papal States) lie in the late seventh century, when popes and the Roman nobility created a "Republic of St. Peter," a state separate from other regional powers such as the East Roman or Byzantine empire and Lombardy. Over the next millennium, the papacy (representing administrative authority in Rome) exercised varying degrees of control over territory, eventually extending across the middle section of the Italian peninsula. It, along with other independent Italian principalities and kingdoms, dissolved in the Italian unification movements of the mid-nineteenth century. At that time, approximately three million persons inhabited the 16,000 mi² of territory that comprised the Papal States.
The Roman States issued its first postage stamps in 1852. Other Italian principalities such as the kingdom of Piedmont-Sardinia, Tuscany, Naples, Modena, and Sicily also issued postage stamps (franco bollo).
The 1952 stamp design includes an image of a mail coach and driver pulled by four horses and reproduces a Roman States stamp design with the papal insignia and the value of 50-bajocchi (one hundred bajocchi to the scudo, the common unit coinage in the Papal States). The horizontal stamp measures 4 cm. x 3 cm, and the overall dimensions of the souvenir sheet are 11.2 cm. x 12.2 cm. The colors included in the stamp design are black on an ivory background, with the Roman States stamp reproduced in blue/cream (or purple). The Crossed Keys of St. Peter watermark the stamp. Perforations measure 13 x 13 1/4 for the single stamp and 13 x 12 1/2 for stamps in the souvenir sheet.
Corrado Mezzana designed the stamp, which Mario Canfarini engraved. Printing was done by lithography (recess). Polish artist Casimir Dabrowska designed the souvenir sheet, which was printed by photogravure. The Vatican issued a total of 225,000 stamps and 200,000 souvenir sheets. The stamps were valid for use until withdrawn from sale on December 31, 1953.
Sources:
"Vatikanstaat," in Michel Europa Katalog, Band 3, Südeuropa, Unterschleißheim, Germany, Schwanberger Verlag GMBH, 2008.
"Vatican City," in Stanley Gibbons Stamp Catalogue, part 8, Italy and Switzerland, 7th edition, Ringwood, Hampshire, England, 2010.
"Vatican City," in Scott Standard Stamp Catalogue, volume 6, Sidney, OH, Scott Publishing Company, 2006.
Francis F. X. Noble. The Republic of St. Peter: The Birth of the Papal State. Philadelphia: University of Pennsylvania Press, 1984.
Floyd S. Jenkins, S. J. "Introduction to the Philately of the Roman States." http://www.vaticanphilately.org/rs.htm#POLITICALHISTORY
