Eusebius of Caesarea (ca. 260–ca. 340), one of the early church’s great polymaths, produced significant works as a historian (Ecclesiastical History), geographer (Onomasticon), philologist, exegete (commentaries on the Psalms and Isaiah), apologist (Preparation for and Demonstration of the Gospel) and theologian. His Commentary on Isaiah is one of his major exegetical works and the earliest extant Christian commentary on the great prophet. Geographically situated between Alexandria and Antioch, Eusebius approached the text giving notable attention to historical detail and possible allegorical interpretation. But above all, employing the anologia fidei, he drew his readers’ attention to other passages of Scripture that share a common vocabulary and theological themes, thus allowing Scripture to interpret Scripture. Here, for the first time in English, Jonathan Armstrong provides readers with a highly serviceable translation of Eusebius’s notably difficult Greek text, along with a helpful introduction and notes.