Lucius Caecilius Firmianus Lactantius (c. 250 – c. 325) was an early Christian author who became an advisor to the first Christian Roman emperor, Constantine I, guiding his religious policy as it developed, and a tutor to his son. 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.
