Gibraltar-Vatican Joint Issue
The Vatican City State issued its first stamps in 1929, the same year that it was established under the Lateran Treaties. It released its first joint issue in 1969. Joint issues of stamps by the Vatican and other countries were uncommon for most of the twentieth century. In 2000, the Vatican and Poland released a joint issue designed by Czeslaw Slania which commemorated the eightieth birthday of John Paul II. However, the early twenty-first century saw a substantial increase in joint issues. In 2003, a set released by the Vatican and Poland celebrated the twenty-fifth anniversary of John Paul II's pontificate. The following year, a joint issue of the same countries commemorated the pope's return visits to Poland. In 2005, five of the eleven stamp sets released by the Vatican were joint issues. There have also been joint issues with Germany since Benedict XVI became Pope. In 2011, the Vatican and Croatia released a joint issue which commemorated the tercentenary of the birth of Rugerius Boscovich (1711 – 1787).
Catholic Church
The Italian unification of the 1860s incorporated the Papal States, including Rome itself from 1870, into the Kingdom of Italy, thus ending the papacy's millennial temporal power. In response, Pope Pius IX excommunicated King Victor Emmanuel II, refused payment for the land, and rejected the Italian Law of Guarantees, which granted him special privileges. To avoid placing himself in visible subjection to the Italian authorities remained a "prisoner in the Vatican". This stand-off, which was spoken of as the "Roman Question", was resolved by the 1929 Lateran Treaties, whereby the Holy See acknowledged Italian sovereignty over the former Papal States in return for payment and Italy's recognition of papal sovereignty over Vatican City as a new sovereign and independent state.