Offers a synoptic review of Constantine's relation to all the cultic and theological traditions of the Empire during the period from his seizure of power in the west in 306 CE to the end of his reign as autocrat of both east and west in 337 CE~Provides a reference work for those studying the ecclesiastical and theological developments and controversies of the fourth century~Addresses questions such as: can we find in this era any strategy of religious toleration, or a notion of Christianity as one among many religions? Is there a legitimate application in this period for such terms as 'conversion' or 'hybridity'? And how far was Christianity commensurable with the practices and systems of thought sometimes portrayed as its rivals?