Constantine the Great is one of those rare historical figures who is nearly as controversial today as he was in his own time. Lauded, both then and now, as a military hero who ended the brutal persecutions of Christians and as the first Roman emperor to himself embrace Christianity, Constantine is just as often vilified as a destructive innovator, a coddler of heretics, and a tyrannical hypocrite with the blood of his own family on his hands. The Life of the Blessed Emperor Constantine was penned shortly after the emperor’s death in AD 337 by the great Church historian Eusebius Pamphilus, bishop of Caesarea. Though criticized as mere panegyric lionizing Constantine’s virtues while ignoring his flaws, Eusebius’s Life is nonetheless the most substantial and detailed biography of the first Christian emperor to come down to us from antiquity. The work is also the sole source for several key episodes in Constantine’s life–including the emperor’s famous vision of a cross in the sky accompanied by the words, Conquer by this.