The imperial towns--which, from the twelfth to the fourteenth century, after having freed themselves from the fetters of feudalism, had risen to such a height of independence that the emperor himself had but a nominal supremacy over them--were Ratisbon, in Bavaria; Augsburg and Ulm, in Swabia; Nuremberg, Spiers, Worms, and Frankfort-on-the-Main, in Franconia; Magdeburg, in Saxony; Hamburg, Bremen, and Lubeck, in the Hanseatic League; Aix-la-Chapelle, Bonn, Cologne, Coblentz, Mayence, Strasburg, and Metz, in the Rhenish and Lotharingian provinces. These towns, essentially industrial and commercial, in which the middle-classes were for the most part supreme, formed vast emporiums, teeming with the products of the north, the south, and the east. They were looked upon as the store-houses and arsenals of Europe. Feudalism, unable to produce anything for itself, was always replenishing from these depôts the resources necessary for equipping and revictualling its armies. From them came the arms and the engines of warfare, as well as the special workmen, the cross-bowmen, the carpenters, the founders, and the artillerymen, who composed the _personnel_ of the artillery at this period. If the free towns had arrived at a common understanding, and formed a pacific league between themselves, they would have presented a serious obstacle to the struggles of the suzerain lords; but their distance from each other, especially those in the centre of Germany, prevented them from coming to such an arrangement. Nor could they, as in England, form an alliance with the feudal nobility, nor, as in France, make common cause with the suzerain. As the emperor left them to act independently, they were obliged to organize their own defence, to contract alliances with some powerful neighbour, and weaken, by dividing them, those enemies whom they deemed stronger than themselves. Thus these free towns never constituted a homogeneous body; they were isolated and spread over a vast extent of territory, being only brought together by feelings of interest and sympathy, but without any mutual tie or political cohesion. The lord with whom they were at war to-day, would enter their service and pay the next, with the title of _soldarien_; and at times a single town would have as many as two or three hundred of these allies, who were always followed by a swarm of marauders, and who spread desolation throughout the land. The lords who were without fortune, who represented the petty feudalism of the country districts, finding in the service of these towns a means for keeping up their state and paying their followers, passed from one to the other, and only enlisted under the standard of a sovereign prince for want of better employment, for the latter did not as a rule pay so well as these free towns.