Life of Constantine (Vita Constantini) is a panegyric written in honor of Constantine the Great by Eusebius of Caeserea in the 4th century AD. It was never completed due to the death of Eusebius in 339. The work provides scholars with one of the most comprehensive sources for the religious policies of Constantine's reign. In addition to detailing the religious policies of the Roman Empire under Constantine, Eusebius uses Life of Constantine to engage several of his own religious concerns, such as apologetics, as well as a semi-bibliographic account of Constantine. The reliability as a historical text has been called into question by several historians, most notably Timothy Barnes, throughout history, due to its questionable motives and writing style.