Diplomatic rank is a system of professional and social rank used in the world of diplomacy and international relations. A diplomat's rank determines many ceremonial details, such as the order of precedence at official processions, table seatings at state dinners, the person to whom diplomatic credentials should be presented, and the title by which the diplomat should be addressed. International diplomacy Ranks The current system of diplomatic ranks was established by the Vienna Convention on Diplomatic Relations (1961). There are three top ranks, two of which remain in use: Ambassador. An ambassador is a head of mission who is accredited to the receiving country's head of state. They head a diplomatic mission known as an embassy, headquartered in a chancery usually in the receiving state's capital. A papal nuncio is considered to have ambassadorial rank, and presides over a nunciature. Commonwealth countries send a high commissioner who presides over a high commission and has the same diplomatic rank as an ambassador. Minister. A minister was a head of mission who was accredited to the receiving country's government. A minister headed a legation rather than an embassy. After World War II, the embassy became the standard form of diplomatic mission, and the rank of minister is now obsolete. Many countries use the title minister-counsellor to refer to the deputy head of a mission, but does not hold the rank of minister. An envoy or an internuncio is also considered to have the rank of minister. Chargé d'affaires: A chargé d'affaires en pied is a permanent head of mission who is accredited by their country's foreign minister to the receiving nation's foreign minister, in cases where the two governments have not reached an agreement to exchange ambassadors. A chargé d'affaires ad interim is a diplomat who temporarily heads a diplomatic mission in the absence of an ambassador. The body of diplomats accredited to a country form the diplomatic corps. Ambassadors have precedence over chargés, and precedence within each rank is determined by the date on which diplomatic credentials were presented. The longest-serving ambassador is the dean of the diplomatic corps, who speaks for the entire diplomatic corps on matters of diplomatic privilege and protocol. In many Catholic countries, the papal nuncio is always considered the dean of the diplomatic corps. Historical ranks, 1815–1961 The ranks established by the Vienna Convention (1961) modify a more elaborate system of ranks that was established by