Holy See of the East of Rome also claims the title of the Catholicos and the Holy Apostolic See of St. Thomas. Patriarch Mar Addai II, is the Catholicos of the Ancient Church of the East. The current Seat of the Catholicos of Ancient Church of the East is in Baghdad, Iraq. The official title of the Head & Father of the Syro-Malabar Catholic Church is "the successor to the Holy Apostolic See of St. Thomas and the Gate of All India". The church is headed by the Major Archbishop of Ernakulam-Angamaly, Cardinal Maran Mar George Alencherry. The current Seat of the Major Archiepiscopal Curia
Holy See former Secretary for Relations with States, said that the Vatican City is a "minuscule support-state that guarantees the spiritual freedom of the Pope with the minimum territory". The Holy See, not the Vatican City, maintains diplomatic relations with states. Foreign embassies are accredited to the Holy See, not to the Vatican City, and it is the Holy See that establishes treaties and concordats with other sovereign entities. When necessary, the Holy See will enter a treaty on behalf of the Vatican City. Under the terms of the Lateran Treaty, the Holy See has extraterritorial authority over various sites in Rome