What were the causes and major consequences of the revitalization of western Europe in the period after the 11th century?

The 11th century saw an increase in agricultural productivity associated with the clearing of forests. This led to an expansion in the amount of land able to produce grain, and it also coincided with new practices of systematic crop rotation; these practices improved the crop-yield ratio from 2:1 to 3:1. This increased agricultural production supported steady growth in population and created modest surpluses, which could be traded for various tools, textiles, and other products. The disappearance of slave labor and limitations on serf labor stimulated labor saving technological innovation, such as the building of thousands of water mills in Europe.
The growth of foreign and domestic trade increased the circulation of money and, together with the emergence of money lending, made possible the financing of a new construction boom. Towns and cities expanded, and artisans built many new stone churches and castles. Feudal anarchy and warfare gradually decreased as the influential Peace of God movement spread, and the relationships between lords and vassals stabilized.
Compared to previous periods, there were fewer devastating foreign invasions after the defeat and Christianization of the Magyars and their gradual transition to a more settled way of life. The Viking incursions also subsided, due to the rise of Scandinavian monarchies and a noted improvement in defense tactics in continental Western Europe with the emergence of mobile knights and their effective horseback fighting techniques.
At the same time, the expansion of Cluniac monasticism stimulated economic and financial activity; these monasteries were productive economic units that engaged in financial operations and loaned money on a significant scale. Guilds developed and a new communal movement in the cities started to liberate artisans and merchants from feudal overlords and arbitrary exploitation. These developments provided some property protection for city dwellers, increasing the favorable atmosphere for urban economic growth.