St. Ephrem born at Nisibis in Mesopotamia of a pagan father, was cast out of his home and lived as a hermit in the desert. He never became a priest but was a deacon of the Church of Edessa. From early times, because of his opposition to the Arians, he had been famed as a teacher of the Universal Church; not only the Syrians, but the Byzantines, the Slavs, the Armenians, and the Copts had incorporated in their liturgical books the melodious compositions of the celebrated Deacon of Edessa, who was called in consequence by the Eastern Church the “Lyre of the Holy Spirit.”

He died at Edessa in 379. In 1918, the year in which the Centenary of St. Jerome was being kept, Pope Benedict XV compared these two heroic monks of the East. On October 5, 1920, this same Pope proclaimed St. Ephrem a Doctor of the Church. He is the only Deacon honored with the title Doctor.
(Source: The New Roman Missal by Father Lasance)