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.
Joseph VI Audo
In the early 19th century there was not yet a formal union between the two patriarchal lines that professed to be in communion with the Holy See. The ancient monastery of Rabban Hormizd, that for many centuries was the see of the Mama patriarchal family supported by most of the East Syrian Christians, in 1808 recognized as its own patriarch Mar Augustine Hindi, the leader of a patriarchal line started by Mar Joseph I in 1681 in union with Rome. This was fiercely opposed by the last descendant of the Mama family, Yohannan Hormizd, also in communion with Rome. Joseph Audo was a partisan of Mar Augustine Hindi and thus became an active opponent of Yohannan Hormizd: the strong conflict came to an end only through the direct intervention of two apostolic delegates sent by Rome in 1828-1829.