>>24681924
Pic related is the best place to start.
>how and why Pagan religions were conquered by Christianity
The why has two points. Firstly, native religions don't have the same structure as christianity, which is a creedal ideology centred on organisations. Native religion at the time was about traditional customs and ceremonies, not a creed, so there was simply no widespread awareness at the time that an organisation would try to control their mind, much less use extreme political and military pressure to do so. The closest analogue would be Roman attacks against the order of the druids, but that was a political move done to stop Celtic organisation and resistance. In short, they didn't know their enemy - the entire worldview was too alien for that. Nobody called themselves a pagan, that term just means 'not christian', synonymous with gentile. Their world was defined by tribal bonds, not an ideological 'brotherhood' like christianity.
Secondly, christianity got going in the first place because Greco-Roman civilisation failed and failed hard. They were already in religious crisis for many centuries. The Romans destroyed their original religion and obviously copied Greek religion very early in their history, and the only remnant is the myth of Romulus. Roman priests weren't even religiously authentic, they were politicians who got elected to the position to climb the socia ladder. Greek culture fell to a degenerate worldview most clearly seen Parmenides and Plato, with its heavy emphasis on static being. This philosophy is far more in line with the judeo-christian worldview, and indeed Plato's influence on the hebrew bible is well known. It didn't begin with them though, this increasingly inorganic view was a development over thousands of years and was strongest in the eastern mediterranean through to Persia.

[1/2]