Foreign relations of Serbia are accomplished by efforts of the Ministry of Foreign Affairs. Serbia has inherited the Ministry of Foreign Affairs, along with all of its holdings, after the dissolution of the previous state union with Montenegro. Serbian foreign ministries continue to serve citizens of Montenegro in countries that do not have Montenegrin diplomatic presence. The governments of Serbia and Montenegro expressed an interest in pursuing a common foreign policy. Former President of Serbia Boris Tadić referred to relations with the European Union (EU), Russia, United States and China as the four pillars of foreign policy. Serbia joined the United Nations on 1 November 2000. History Medieval Serbia In the centuries prior to Ottoman rule in the country, medieval Serbian states established diplomatic relations with a number of states in Europe and the Mediterranean, particularly under the Nemanjić dynasty, during which time the Serbian Empire reached its greatest extent. Serbian envoys regularly embarked on missions to states near and far, typically in large entourages bearing gifts for the foreign courts. One such embassy to the Mamluk Sultanate of Egypt arrived in Cairo bearing gifts including five hawks, five falcons, four silver cups, and an extravagantly ornamental sword. Serbian diplomats of the time were mostly drawn from two groups; those sent to the Catholic West primarily hailed from noble families from the coastal cities of the Adriatic Sea, such as Kotor, Dubrovnik, and Bar, and those sent to the Orthodox East were frequently members of the clergy, like Saint Sava. Typically the rulers of these states would provide dwellings for the envoys and their entourages, as well as transportation. Serbian Revolution and Autonomous Principality (1804–1878) Serbia gained its partial independence from the Ottoman Empire in two uprisings in 1804 (led by Đorđe Petrović – Karađorđe) and 1815 (led by Miloš Obrenović), although Turkish troops continued to garrison the capital, Belgrade, until 1867. In 1817 the Principality of Serbia was granted de facto independence from the Ottoman Empire. High officials in the Austro-Hungarian Empire lobbied for Ottoman approval of the liberal 1869 constitution for Serbia, which depended on the Porte for final approval. Vienna's strategy was that a liberal political system in Serbia would divert its impulse to foment nationalist unrest within its neighbors, and also delay its efforts to gain territory at the expense of the Ottoman Empire. Principality/Kingdom of Serbia (1878–1918) The Autonomous Principality became an internationally recognized independent