Yohannan VIII Hormizd
Mar Yohannan VIII Hormizd (often referred to by European missionaries as "John Hormez" or "Hanna Hormizd") (1760–1838) was the last hereditary patriarch of the Eliya line of the Church of the East and the first patriarch of a united Chaldean Church. After succeeding his uncle Eliya XII Denha in 1780 as patriarch of Mosul, he made a Catholic profession of faith and was recognised in 1783 by the Vatican as patriarchal administrator and archbishop of Mosul. His career as patriarchal administrator was controversial, and was marked by a series of conflicts with his own bishops and also with the Vatican. Suspended from his functions in 1812 and again in 1818, he was reinstated by the Vatican in 1828. In 1830, following the death of the Amid patriarchal administrator Augustine Hindi, he was recognised by the Vatican as "patriarch of Babylon of the Chaldeans" and the Mosul and Amid patriarchates were united under his leadership. This event marked the birth of the since unbroken patriarchal line of the Chaldean Catholic Church. Yohannan Hormizd died in 1838 and his successor Nicholas I Zaya was chosen by the Vatican, ending the centuries-old practice of hereditary succession in the Eliya line of the Church of the East.
Yohannan VIII Hormizd
On the following day his nephews Ishoyahb and Yohannan both made Catholic professions of faith and were reconciled. Despite the late patriarch's preference the Latin missionaries supported Ishoyahb, who shortly afterwards succeeded his uncle as patriarch, taking the name Eliya XIII Ishoyahb, without open opposition from the young Yohannan. In May 1779, as soon as he had obtained his "firman" of office from the Ottoman civil authorities, Ishoyahb abandoned his Catholic profession of faith. The notables of Mosul, with the support of the Latin missionaries, deposed him and unanimously chose Shemon of Amid, the Chaldean metropolitan of Mardin (1758–88), as patriarch in his place. Shemon however declined to accept the honour, and Ishoyahb’s opponents were obliged to turn instead to the young Yohannan Hormizd, who had demonstrated his zeal for the Catholic cause since Ishoyahb's "volte face" by converting the Nestorians of the large Erbil villages of Aïnqawa, Armuta and Shaqlawa to Catholicism and encouraging them to withdraw their loyalty from his cousin. Yohannan was elected patriarch in 1780, and his supporters bribed the governor of Mosul to use his influence to obtain a firman from Constantinople, granting him authority over both the Chaldean Christians and the Nestorians. Yohannan then sent a profession of faith and a letter of submission to the Vatican.