To centralize finance and centralize trade

It could well be argued the culprit in European history was the power of the monarchs towards the end of the 13th century to centralize finance by outlawing local currencies and to centralize trade by granting charters to corporations that served the crown and monopolized real economic activity. The result was the impoverishment of the populations and the destruction of the homeostasis in the towns and countries across Europe, which eventually led to: 

• the plague; 
• the empowerment of the rulers, be they secular or clerical, that led to centuries of wars and schisms; 
• the development of a permanent upper class that funded the arts and sciences of the Renaissance, but which also led to 
• the promotion of an ideology of individualism that celebrated hubris and excess and cultivated a perspective on human possibility that understood it as ruthless and grasping. 

It could be that at the end of the 13th century Europe locked in the might of the ruling class and began the ancien regime's slow descent that we are only now beginning to realize was a big mistake.