Originally published in 1929, this book was formed from the content of the Thirlwall Prize Essay for 1927. It presents a series of studies covering various aspects of the life and work of Eusebius. The text is divided into two main sections, with the first part dealing with the life of Eusebius up until the end of the Great Persecution and the second focusing on his position in the Arian controversy. Detailed notes are incorporated throughout. This book will be of value to anyone with an interest in Eusebius and the history of early Christianity.