What you guys failed to answer was the question of "why?"
The answer stretches across hundreds of years and has its roots in the decline of power of the western half of the Roman empire. The Roman Empire grew to the point that effective governing wasn't possible given the travel distances and multiple sub-cultures. Typically, after a Roman army captured a region, it pretty much let people continue doing what they had been doing, but using a common currency, sharing common defense, and paying a tribute to the empire for various services it provided. This made it easier to rule the hearts of the people, but it also gave the empire a whole circus of sub-cultures with differing laws and ways of doing business. Eventually it was realized that the empire would have to be split in two halves, with one seat in Rome and the other in Constantinople. Still, the empire continued to grow and eventually even this arrangement became unworkable and peoples' welfare began to decline, resulting in the folks losing faith in their government to provide them the basic services they wanted.
As the seat of power was eroded, the people began to turn to local government to provide the services that the Empire had provided earlier. Priests, who had always maintained a limited sort of power over people, began to gain more trust and power in the local communities as "official" government began to falter. People would turn to their priests for arbitration of disputes, or recognition of transfers of property, and so forth. It also became vogue for the local nobleman to make monetary donations to the local church as a way to show to his fellow citizens that he was "one of the good guys". Eventually, as the churches got richer, they were able to provide more services, and thereby won the hearts of more people, and thereby became more powerful in making the decisions of how things should be run in the community. Who would you follow: the guy who answers to a far-away governor, or the guy that you see every week who can provide you services right now?
Along this same time came the concept of converting the barbarian Germans and Vikings to Christianity, which was made easier by the fact that the cross was very similar to symbols used by the barbarian priests (that happened to be based on the general shape of a Germanic broadsword). As the barbarian kings adopted Christianity, the popularity of the Christian faith increased, as did the power of the churches and the adoption of the Catholic faith (itself an amalgamation of the various genres of Christianity in practice at the time) as the single, recognized "official" religion.
Meanwhile, the eastern half of the empire, seated in Constantinople (named for the Emperor Constantine), pretty much continued as it had, except that their faith became what is known as "Greek Orthodox".
Trivia: the Russian word "czar" is a derivative of "Caesar".
So what do you think of Governor Jeb Bush's plan to turn more of the Florida social welfare programs over to private church-sponsored organizations? Are we going the way of the Romans?
