Page:General History of Europe 1921.djvu/331

 The Crusades: Heresy and the Mendicant Orders 243 Italian merchants, they found their way into France and Ger- many, suggesting ideas of luxury hitherto scarcely dreamed of by the still half -barbarous Franks. 393. Effects of the Crusades on Warfare. Moreover, the Crusades had a great effect upon the methods of warfare, for the soldiers from the West learned from the Greeks about the old Roman methods of constructing machines for attacking castles and walled towns. This led to the construction in western Europe of stone castles, first with square towers and later with round ones, the remains of which are so common in Germany, France, and England. The Crusades also produced heraldry, or the rules for the use of "coats of arms." These were the badges that single knights or groups of knights adopted in order to distinguish themselves from other people. 394. Other Results of the Crusades. Some of the results of the Crusades upon western Europe must already be obvious, even from this very brief account. Thousands and thousands of French- men, Germans, and Englishmen had traveled to the Orient by land and by sea. Most of them came from hamlets or castles where they could never have learned much of the great world beyond the confines of their native village or province. They sud- denly found themselves in great cities and in the midst of un- familiar peoples and customs. This could not fail to make them think and give them new ideas to carry home. The Crusade took the place of a liberal education. The crusaders came in contact with those who knew more than they did, above all, the Arabs, 1 and brought back with them new notions of comfort and luxury. III. THE HERETICS AND THE FRIARS 395. Rise of Heresy. During the period of the Crusades the Church faced a new danger at home. Leaders began to arise who attacked its institutions and beliefs and strove to induce men to join them in their revolt. Those who questioned the teachings of 1 The western Europeans derived many important ideas from the Mohammedans in Spain, as Arabic numerals, alchemy, algebra, and the use of paper.