Lucius Caecilius Firmianus signo Lactantius (c. 250 – c. 325) was an early Christian author who became an advisor to Roman emperor, Constantine I, guiding his Christian religious policy in its initial stages of emergence, and a tutor to his son Crispus. His most important work is the Institutiones Divinae (“The Divine Institutes”), an apologetic treatise intended to establish the reasonableness and truth of Christianity to pagan critics. [Description from Wikipedia]