At the time of Constantine the Great (r. 306–337), barely 10% of the Roman Empire's population were Christians, with most of them being urban population and generally found in the eastern part of the Roman Empire. The majority of people still honoured the old gods in the public Roman way of "religio". As Christianity became a complete philosophical system, whose theory and apologetics were heavily indebted to the Classic word, this changed. In addition, Constantine, as Pontifex Maximus, was responsible for the correct "cultus" or "veneratio" of the deity which was in accordance with former Roman practice. The move from the old religion to the new entailed some elements of continuity as well as break with the past, though the artistic heritage of paganism was literally broken by Christian zeal.