While political power centralized during the 12th and 13th centuries, the energies and talents of Europe were gathering in one of civilization’s great bursts of development. Stimulated by commerce, a surge took place in art, technology, building, learning, exploration by land and sea, universities, cities, banking and credit, and every sphere that enriched life and widened horizons. Those 200 years were the High Middle Ages. ~ American historian Barbara Tuchman
Bouts of prosperity have repeatedly ended because of greed gone overboard and grasping governance. In the instance of medieval Europe, a perfect storm of misfortune swept the continent.