The
Ancient Church of the East (
ʿĒdtā ʿAttīqtā d'Maḏnəḥā, ,
Kanīsa al-Mašriq al-qadīma), officially the
Ancient Holy Apostolic Catholic Church of the East (ܗܝ ܥܕܬܐ ܣܘܪܝܝܬܐ ܕܐܫܬܬܐܣܬ ܒܫܢܬܐ) distinguished itself from the
Assyrian Church of the East in 1964. It is one of the
Assyrian churches that claim continuity with the historical
Patriarchate of Seleucia-Ctesiphon – the
Church of the East, one of the oldest Christian churches in Mesopotamia. The church is headquartered in Baghdad, Iraq. In 1970, Catholicos-Patriarch
Mar Addai II Giwargis succeeded
Mar Thoma Darmo (1968–1969).