
BZ C. answered 02/16/20
Eccentric and Lovable Historian of Politics and Ideas
The medieval Church was actually not that very powerful. It lacked a formal army. What it had was bureaucracy. Some important themes to keep in mind when examining the medieval Church. It could be very effective when allied to some secular power. The Church could outlast secular opponents even if it was unlikely to do well in the short run. Finally, the Church was very vulnerable to rising states once they formed sophisticated bureaucracies. So for example, the Church was never able to pursue heretics on its own. The Church was able to turn the investiture controversy into a draw in the long run even as it paid a heavy price for the conflict. The Church had very little control over Crusading armies. The fact that the Church had to call for Crusaders tells you how little military power it had on its own.