The Assyrian Church of the East is a Nestorian Christian church which is active in the Middle East and India. It was founded in 1552 as the result of a split within the Nestorian Church of the East, and it maintained the Nestorian theology, while the other faction rejoined the Catholic Church. The Assyrian Church of the East uses Syriac as its liturgical language, and the majority of its adherents are ethnic Assyrians. The church has an archdiocese of India, and its main base in the Middle East consists of northern Iraq, southeastern Turkey, northeastern Syria, and northwestern Iran, with Erbil, Iraq serving as its center. It had 323,300 adherents by the 2010s.