<P> In 380 , under Theodosius I , Nicene Christianity became the official state religion of the Roman Empire . Christian heretics as well as non-Christians were subject to exclusion from public life or persecution , though Rome 's original religious hierarchy and many aspects of its ritual influenced Christian forms , and many pre-Christian beliefs and practices survived in Christian festivals and local traditions . </P>
<P> In 380 , under Theodosius I , Nicene Christianity became the official state religion of the Roman Empire . Christian heretics as well as non-Christians were subject to exclusion from public life or persecution , though Rome 's original religious hierarchy and many aspects of its ritual influenced Christian forms , and many pre-Christian beliefs and practices survived in Christian festivals and local traditions . </P>
when did rome begin following a monotheistic religion
when did rome begin following a monotheistic religion
380
380