ABSTRACT
The medieval practice of making pilgrimages to the Holy Land began in the fourth century and soon there even guide-books for the pilgrims. In addition to the numerous pilgrimages to the Holy Land, other movements of the eleventh century helped to popularize the idea of the crusades. Even more important in anticipation of the crusades were the wars waged by the Christians against the Moslems in Spain. During the two centuries of the crusades the life of Europe was greatly altered. The technique of business was improved and devices like the bill of exchange and double-entry book-keeping were introduced. Intended to destroy forever Mohammedan power in the East, they really contributed to strengthen it. The crusades inaugurated the series of explorations and discoveries which led to the penetration of Asia, the discovery of America, the rounding of the Cape of Good Hope and the discovery of a water route to India and China.
