Chicago (AINA) -- The Patriarch of the Holy Apostolic Catholic Assyrian Church of the East, His Holiness Khanania Dinkha IV, died Thursday at 10:04 AM at the Mayo Clinic in Rochester, Minnesota. The cause of death was a virus infection and pneumonia. The Bishop of India, Mar Aprim Mooken, will serve as acting patriarch until a new patriarch is elected.

The funeral service will be held on April 8 at St. George Church in Chicago.

Patriarch Dinkha, the 111th Patriarch of the Church of the East, was consecrated as Patriarch on October 17, 1976, serving 39 years at his post. His tenure was the tenth longest in church history. He moved the Holy See of the Church of the East to Morton Grove, a suburb of Chicago, shortly after his consecration because of political instability in Iraq.

Patriarch Dinkha was born in Iraq on September 15, 1935. He was ordained a priest on July 15, 1957 and appointed to the ministry in Urmia, Iran. He was consecrated as bishop on February 11, 1962. He became patriarch after Patriarch Eshai Shimun was assassinated in 1976.

Patriarch Dinkha is credited with rebuilding the church, which had neared the brink of destruction after the assassination of his predecessor. He translated portions of the liturgy from classical Assyrian (Syriac) to modern Assyrian and brought stability and peace to a church in turmoil.

Patriarch Dinkha was a warm, fatherly figure and a role model for members of the Church of the East. His yearly Christmas and Easter epistles would stress the national Assyrian identity of the three major Assyrian denominations -- the Church of the East, the Chaldean Church of Babylon and the Syriac Orthodox Church. He enjoined members of the church to be faithful citizens of all countries in which they reside, and he would always be thronged by supporters wherever he visited. His most eternal message was that of ecumenism, which he was passionate about, and the desire to see all Apostolic Churches in communion with one another as equals, accepting each other's sacraments and consecrations.

Patriarch Dinkha met with Pope John Paul II on several occasions, Pope Benedict, Pope Francis, Russian Orthodox Patriarch Kirill, Patriarch Sako of the Chaldean Church, Patriach Karem of the Syrian Orthodox Church, Patriarch Yonan of the Syriac Catholic Church, as well as the previous Chaldean Patriarchs Daley and Bidawid.

Under his reign, the Church of the East signed a Common Christological Declaration with the Roman Catholic Church, then headed by Pope John Paul II.

On September 16, 2008 Patriarch Dinkha conducted a prayer service at the Syriac Orthodox Church in Brussels. Citing the continuing attacks on Assyrians in the Middle East, he called for the establishment of an Assyrian-administered unit in Iraq's Nineveh Plains and unity of Assyrians from different denominations.

The Mayor of Chicago, Rahm Emanuel, sent the following letter of condolence to the Church:

Editors note: this article was edited to add the letter from Chicago Mayor Rahm Emanuel, and to remove the last two paragraphs.