After the assassination of Mar Eshai Shimun XXI, the Church of the East had an urgent need to restore its leadership.
In 1976, the prelates of the church convened in London to elect a new Catholicos Patriarch and chose Dinkha as the most qualified candidate to fill the post.
He was consecrated on 17 October 1976, in the West London Church of St. Barnabas, Ealing.
With this consecration, Mar Dinkha IV became the successor to the Apostolic see of Seleucia-Ctesiphon (Babylon).
He also announced that the hereditary line of succession for the Patriarchy which had existed for 500 years was discontinued with his tenure, allowing any cleric from the Church of the East to be elevated to Catholicos-Patriarch.

Dinkha established headquarters—along with four other houses of worship—in Chicago, Illinois, United States, in part due to the instability of the Iran–Iraq War.
This conflict as well as Saddam Hussein's policy of Arabization in Iraq, the Gulf War and subsequent sanctions against Iraq intensified the Assyrian diaspora from the region.
Meanwhile, the Islamic Revolution and Shi'a emphasis in Iran created a tense situation for Assyrians in the Middle East.
During the reign of Shimun XXI and Dinkha IV, American membership in the Church of the East rose from 3,200 in the 1950s to approximately 100,000 in 2008.

In 2005, the Patriarch conducted discussions with President of Iraqi Kurdistan Masoud Barzani on returning to the Apostolic See in northern Iraq and constructing a new residence in Ankawa.
On 15 July 2007, Mar Dinkha celebrated 50 years of his priesthood.
A ceremony was held at St. George Cathedral in Chicago, where a portion of Ashland Avenue was renamed "His Holiness Mar Dinkha IV Blvd".
In 2008, he received an honorary degree from the University of Chicago, in part because of his emphasis on education—he stated a goal of only appointing theologians with doctoral degrees to the position of bishop.
After the assassination of Mar Eshai Shimun XXI, the Church of the East had an urgent need to restore its leadership. In 1976, the prelates of the church convened in London to elect a new Catholicos Patriarch and chose Dinkha as the most qualified candidate to fill the post. He was consecrated on 17 October 1976, in the West London Church of St. Barnabas, Ealing. With this consecration, Mar Dinkha IV became the successor to the Apostolic see of Seleucia-Ctesiphon (Babylon). He also announced that the hereditary line of succession for the Patriarchy which had existed for 500 years was discontinued with his tenure, allowing any cleric from the Church of the East to be elevated to Catholicos-Patriarch.
Dinkha established headquarters—along with four other houses of worship—in Chicago, Illinois, United States, in part due to the instability of the Iran–Iraq War. This conflict as well as Saddam Hussein's policy of Arabization in Iraq, the Gulf War and subsequent sanctions against Iraq intensified the Assyrian diaspora from the region. Meanwhile, the Islamic Revolution and Shi'a emphasis in Iran created a tense situation for Assyrians in the Middle East. During the reign of Shimun XXI and Dinkha IV, American membership in the Church of the East rose from 3,200 in the 1950s to approximately 100,000 in 2008.
In 2005, the Patriarch conducted discussions with President of Iraqi Kurdistan Masoud Barzani on returning to the Apostolic See in northern Iraq and constructing a new residence in Ankawa. On 15 July 2007, Mar Dinkha celebrated 50 years of his priesthood. A ceremony was held at St. George Cathedral in Chicago, where a portion of Ashland Avenue was renamed "His Holiness Mar Dinkha IV Blvd". In 2008, he received an honorary degree from the University of Chicago, in part because of his emphasis on education—he stated a goal of only appointing theologians with doctoral degrees to the position of bishop.
Dinkha IV