EUSEBIUS OF CAESAREA
EUSEBIUS OF CAESAREA, bishop, theologian, historian (ca. 265-ca. 340). One of the most important early fourth-century figures in the Eastern Church and the editor and writer of the preeminent Ecclesiastical History, Eusebius also framed the theology (q.v.) of the Christian Empire that would inform the relations between Church and state throughout the Byzantine era (q.v.) and beyond. He became bishop in ca. 315, and after the enthronement of Constantine (q.v.) was active in not only the shaping of the theory of the Christian Empire, but its day-to-day affairs as well, writing both a Chronicle and a Life of Constantine.
His theology of the Trinity (q.v.), deeply influenced by Origen (q.v.), was the model for most of the Greek episcopate until the synthesis of the Cappadocian Fathers (q.v.). Not a follower of Arius (q.v.), he nonetheless found the homoousios formula of the Creed of Nicaea too radical a departure from what he deemed the norms of trinitarian theology, and thus landed in the camp opposing the great patriarch of Alexandria, Athanasius (q.v.). He is also noted for his important works on Christian apologetics (q.v.), especially the Preparation for the Gospel and the Demonstration of the Gospel (aimed in great part at rebutting the pagan philosopher Porphyry’s Against the Christians), and for his scriptural commentary. Of special value for the Church are his Martyrs of Palestine, which events he personally witnessed, and the Onomasticon, which describes biblical topography.