well, in the heyday of my ancestors, they Celtic and Norse pagans were pretty aggressive, but the Romans take the cake, their aggression covers paganism and Christianity.
this thread contains so many ignorant, partial sided answers i think to fairly answer such a complex question requires a lot of evidence and research, which most if not all replies lack.
and whats that suppose to imply? that an opinion doesnt require evidence? if theres nothing but an opinion, its not gonna add anything to the question.