Antoine-Pierre IX Hassoun

Andon Bedros IX Hassoun (15 June 1809 – 28 February 1884) was an Ottoman prelate of the Armenian Catholic Church, the Armenian rite Catholic Church, who was the Patriarch of Cilicia from 1866 to 1881; he was at the center of a schism that lasted from 1870 to 1879. He was previously archbishop of Constantinople of the Armenian Catholics for twenty years.

In 1880, he became the first cardinal of Armenian descent; he was the first prelate from the Eastern Catholic Churches raised to the College of Cardinals since Cardinal Bessarion in 1439.

He was given responsibility for the Armenian Catholic parish in Smyrna. Later, he was moved to Constantinople where he fulfilled parish assignments. He became chancellor and vicar general of the Armenian Catholic see there, Constantinople of the Armenians.

He was appointed titular archbishop of Anazarbus and coadjutor archbishop of Constantinople of the Armenians on 7 June 1842.

He became archbishop of Constantinople of the Armenians upon the death of Archbishop Paolo Marusci (Maruschian) on 2 August 1846. He chose for his patriarchal name Andon Bedros IX.

Hossoun participated in the First Vatican Council (1869-1870) where he was member of the commission on dogma and supported the definition of papal infallibility. While he was in Rome, dissension within the Armenian Catholic community reached a breaking point. A synod convened at Constantinople in July 1869 failed to take steps to appease the critics of changes in church organization and election procedures, and on 3 April 1870, with support from the Turkish government, formed a separate church. The schism provoked disputes over the ownership of churches, schools and welfare institutions.

Pope Pius IX excommunicated the schismatics on 14 June 1872 and the responded by expelling Hossoun in July and he took refuge in Rome. he received his red galero and was assigned title of Santi Vitale, Gervasio e Protasio on 16 December 1880. He was the first prelate of Oriental rite created cardinal since the promotion of Cardinal Bessarion in 1439.

He resigned as patriarch in June 1881. He died of pleuropneumonia on 28 February 1884 in his residence in Rome.

There is a memorial in the right side of the chapel of Saint Gregory the Illuminator, in the Armenian church of San Nicola da Tolentino agli Orti Sallustiani in Rome; his cardinalitial hat hangs from the ceiling of that church.