 Much of Europe was affected by feudalism in which peasants held tenure from local rulers over the land that they farmed in exchange for military service.The result of this was that they could be called upon, not only for local and regional spats, but to follow their lord to travel across Europe to the Crusades, if they were required to do so.The Crusades, 1095–1270, brought about a very large movement of people and, with them, ideas and trade skills, particularly those involved in the building of fortifications and the metal working needed for the provision of arms, which was also applied to the fitting and decoration of buildings.