The difference in regnal numbers depends on which members of the Shimun family one counts as Patriarchs. March Eshai chose to use the regnal number XXIII)
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"s relocation to Cyprus. In 1940, he relocated again, to Chicago, Illinois in the United States.
March 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 March Thoma was stopped from his duties in the Church of the East. In 1995 March Eshai"s successor, March Dinkha IV, was able to heal the rift.
March Eshai sought to resign as patriarch for health reasons in the late 1960s, but he was persuaded to remain in office. Some activists within the church wanted the patriarch to take a more active role in pushing for a homeland for the Assyrian people, as he had before 1933.
On a separate track, rumors began circulating with those who consistently went against him decided it was time to have someone new.
On 6 November 1975, the patriarch was shot and killed at the door of his home in San Jose, California, by David Malek Ismail. According to trial records, Ismail said he was upset over the patriarch"s marriage. However, the records suggest links between Ismail and church dissidents.
According to Deputy District Attorney Brian Madden, the murder of the patriarch March Shimun was the outcome of a plot among church dissidents.
When the church council met in London on 17 October 1976, it elected as patriarch March Dinkha IV (who had been bishop of Tehran).
