Eusebius of Caesarea

Eusebius of Caesarea (c. 263–339), bishop and scholar, is called the “Father of Church History” for his Ecclesiastical History, the primary record of the church’s first three centuries. A learned biblical geographer and apologist and an adviser to the emperor Constantine, he stood near, though not always within, the Nicene mainstream in the Arian controversy.

Eusebius preserved what would otherwise be lost: his Ecclesiastical History is the indispensable source for the church's first three centuries, quoting documents and authors that have since perished. A learned student of the text, he devised the Eusebian Canons that cross-reference parallel passages among the four Gospels, and his Onomasticon mapped the places of the Bible — early tools that still aid the serious reader of Scripture.