Shimun XXIII Eshai

Mar Eshai Shimun XXIII
His Holiness
Mar Eshai Shimun XXIII
Church	Assyrian Church of the East
Diocese	Patriarchal Diocese of the Eastern United States
See	Apostolic See of Seleucia-Ctesiphon (in exile in San Jose and Chicago)
Installed	1920
Term ended	5 November 1975
Predecessor	Mar Shimun XXII Paulos (1918–1920)
Successor	Mar Dinkha IV (1976–2015)
Orders
Rank	Catholicos-Patriarch
Personal details
Born	26 February 1908 Konak, Hakkari, Ottoman Empire (now Hakkari Province, Turkey)
Died	6 November 1975(1975-11-06) (aged 67) San Jose, California, United States
Nationality	Assyrian
Denomination	Christian, Assyrian Church of the East
Residence	Chicago, Illinois, United States
Occupation	Cleric

Mar Eshai Shimun XXIII (26 February 1908 – 6 November 1975), sometimes known as Mar Shimun XXI Ishaya, Mar Shimun Ishai, or Simon Jesse, was Catholicos Patriarch of the Assyrian Church of the East from 1920, when he was a youth, until his murder on 6 November 1975. (The difference in regnal numbers depends on which members of the Shimun family one counts as Patriarchs; Mar Eshai chose to use the regnal number XXIII.)

Born into the patriarchal family in Qudshanis, in the village of Van, in Ottoman Turkey on February 26, 1908, at the age of 11 Mar Eshai was chosen as patriarch after the death of his uncle during the Assyrian Genocide. He was educated in England, studying theology at Canterbury and at Westcott House, University of Cambridge. He was the translator or author of several books on the theology and history of the Church of the East. The volatile political environment and uncertainties for the church caused in 1933 by the independence of Iraq from colonial rule forced the patriarch to be exiled to Cyprus away from the new see in Bebadi. In 1940, he relocated again, to Chicago, Illinois in the United States. Mar Eshai became an American citizen about 1949 and settled in the San Francisco area in 1954.

In 1964, a dispute over hereditary succession and church calendars caused the metropolitan of the Church of the East in India (known there as the Chaldean Syrian Church) to break away and Mar Thoma was stopped from his duties in the Church of the East. In 1995 Mar Eshai's successor, Mar Dinkha IV, was able to mostly heal the rift. 17% (the Ancient Church of the East) remain separated from the main body of the Church of the East.