The period, then, of the eleventh, twelfth, and thirteenth centuries was one of intense political life, of advanced national self-consciousness, of rich, highly-organized society. It was moreover a period of common ideas, movements, and tendencies over all Europe. Several factors enter into this result: 1. The church was completely organized, forming a common life and teaching everywhere. She had learned to employ the savage vigor and conquering instincts of the northern barbarians as defenses and aggressive missions of her spirit and ideas. The monasteries were homes of learning, and from them issued the didactic literature and the early drama. 2. This resulted in that romantic institution or ideal of chivalry, whose ten commandments explain so much of mediaeval life and art.[1] [1] "Chivalry", by Leon Gautier, 1891, p. 26. (1) Thou shalt believe all the church teaches, and shalt observe all its directions. (2) Thou shalt defend the church. (3) Thou shalt respect all weaknesses, and shalt constitute thyself the defender of them. (4) Thou shalt love the country in which thou wast born. (5) Thou shalt not recoil before thine enemy. (6) Thou shalt make war against the inflael without cessation and without mercy. (7) Thou shalt perform scrupulously thy feudal duties, if they be not contrary to the law of God. (8) Thou shalt never lie, and shalt remain faithful to thy pledged word. (9) Thou shalt be generous and give largesse to every one. (10) Thou shalt be everywhere and always the champion of the Right and the Good against Injustice and Evil. 3. This combination of the Christian and the warrior found its public activity most completely in the Crusades. They gave a common motive and ideal to all the knights of Europe. They brought them together for thinking and for fighting. They spread national traditions and literatures. They made the whole face of Europe and the borders of the Mediterranean known to the ambitious, venturesome, daring, and heroic of every European country. The exploits of chivalric knights were told from camp to camp and taken back home to be told again in the castles. 4. Another institution of feudalism that helped to make this common subject and spirit of mediaeval literature was the minstrel, who was attached to every well-appointed castle. This picturesque poet--gleeman, trouvere or troubadour sang heroic stories and romances of love in the halls of castles and in the market places of towns. He borrowed from and copied others and helped to make the common method and traditions of mediaeval song. 5. Other elements in this result were the extensions of commerce and the growth of traveling as a pleasure. 6. Finally, the itinerant students and teachers of mediaeval universities assisted in the making of this common fund of ideas and material for literature.