The Challenges of Cathedrals

I see five great periods of challenges that cathedrals have gone through. The first was the fall of the roman empire, but everything so collapsed in the four hundreds that the cathedrals that existed then did not survive. The next great challenges, i think, were the vikings, because they caused a lot of havoc in england in the 809 hundreds. Oddly enough, the the vikaries were not particularly hostile to cathedrals, or even christianity. I actually moved into the viking area. And there was clearly much more of a symbiosis between m cathedrals and vikings than you might think.