Civilisations tend to emerge when the conditions are right for that, they tend to build some impressive structures like temples, pyramids, cathedrals, etc and usually dissapear again. The reasons of the collapse may be famines, climate change - drougths, wars, pandemics etc. So here are these Romanesque, Viking, Gothic etc cultures in Europe, at the end of the first century when the climate was friendly, the medieval warming period. And they started building their stone churches and cathedrals, comforming to the usual habits of develloping civilisation. The renaissance was about to begin. But then the usual circumstantial misery started, in the 13th century the medieval warm period had terminated and the Alpine glaciers started to grow rapidly at the onset of the little ice age, Next, there was the bubonic plague, decimating the European population, followed by large scale ergotism or st Anthony fire, less known but just as deadly and sure enough several strong storms still on record brought floodings with high losses. Regional conflicts were many, in short, all the elements were there for the usual collapse of the civilisation meanwhile, what did that civilisation do? It builded higher and more decorated cathedrals, fine art emerged, the great discoverers couldn't wait to discover the rest of the world. Why could the European civilisations thrive where it should have perished as other civilisations did?