Ignatius Aphrem I Barsoum (June 15, 1887 – June 23, 1957) was the 120th Syriac Orthodox Patriarch of Antioch and head of the Syriac Orthodox Church. He wrote, translated and published many scholarly works, including books on the tradition, liturgy, music, and history of Syriac Orthodox Church.
He was born in Mosul, Iraq, and attended a school run by Dominican monks. He studied French and Turkish as well as religious literature and history, and later learned Arabic from studies under Muslim scholars. At the Deir al-Za`faran monastery in Mardin, Turkey, where he started his theological training in 1905, he studied the Syriac language and literature.
After his ordination as a priest in 1908, he remained at the monastery to teach, and in 1911 he assumed the additional responsibility of managing the monastery press. Later that year he began a scholar's visit to the monasteries and churches of Mesopotamia and Turkey. Soon after his return in 1913 he made a similar trip to examine Syriac manuscripts in the great libraries of Europe.
On May 20, 1918, Patriarch Ignatius Elias III consecrated Aphrem as metropolitan Mor Severius and named him the bishop of Syria. Rev. Joel E. Werda led the Assyrian delegation from the USA, representing the Diaspora community in Paris Peace Conference, 1919. He accompanied Bishop Aphrem Barsoum and his secretary. He was disillusioned, however, by the atmosphere of self-interest which prevailed among the delegates representing the European powers, and at one stage of the conference found himself defending not only the rights of the Assyrians, but those of the Arab nations. Though Mor Severius did not succeed in protecting the Assyrian's interests at Paris, the journey gave him ample opportunity for further study of Syriac literature before his return in May, 1920. Two years later, the League of Nations' action making Syria a French mandate brought him the new responsibility of providing for refugees from Cilicia, and he also undertook the building of many new churches in and near Aleppo.