The Holy Apostolic Catholic Assyrian Church of the East (or abbreviated, "Assyrian Church of the East") was born from the missionary work of the apostles St. Thomas from the Twelve, and Ss. Addai & Mari from the Seventy-Two. It was the Church that existed in the Persian Empire, outside of the confines of the limits of the Roman Empire of the west. Its primatial center is Seleucia-Ctesiphon, which was the capital of the Persians. It is an independent patriarchate, not subject to the Bishop of Rome, or any other patriarchate. Thus, it is not Roman Catholic, but ‘catholic’ (meaning ‘universal’) in the sense that the Church was composed of many nations and ethnicities, among them Assyrians, Persians, Jews, Mongols, Turks, etc. The Assyrians who comprise the majority of the ACOE are the descendants of the ancient Assyrians of Mesopotamia mentioned in the Bible; they are the indigenous people of modern Iraq. Their rule stretched from the Mediterranean in the west, and as far as Memphis in Egypt.