Embassy of the United States to the Holy See Embassy of the United States to the Holy See The Embassy of the United States of America to the Holy See (or Embassy Vatican for short) is the diplomatic mission of United States of America to the Holy See, a term referring to the central government and universal reach of the Roman Catholic Church. The current embassy moved to new headquarters in September 2015 in a separate building on the same compound as the United States Embassy Rome. The embassy was previously located on Aventine Hill in the Villa Domiziana in Rome, Italy, which was built as a private residence
Foreign relations of the Holy See diminishing, the number of diplomats accredited to the Holy See grew from sixteen in 1871 to twenty-seven in 1929, even before it again acquired territorial sovereignty with the founding of the State of Vatican City. In the same period, the Holy See concluded a total of twenty-nine concordats and other agreements with states, including Austro-Hungary in 1881, Russia in 1882 and 1907, France in 1886 and 1923. Two of these concordats were registered at the League of Nations at the request of the countries involved. While bereft of territorial sovereignty, the Holy See also accepted requests to act as arbitrator