As for the emperor, he no longer had any power to control his vassals. He could boast of unlimited pretensions and a great past, but he had neither money nor soldiers. At the time of Luther's birth the poverty-stricken Frederick III might have been seen picking up a free meal at a monastery, or riding behind a slow but economical ox team. The real power in Germany lay in the hands of the more important vassals. First and foremost among these were the seven electors, so called because, since the thirteenth century, they had enjoyed the right to elect the emperor. Three of them were archbishops--kings in all but name of considerable territories on the Rhine, namely, of the electorates of Mayence, Treves, and Cologne.[263] Near them, to the south, was the region ruled over by the elector of the Palatinate; to the northeast were the territories of the electors of Brandenburg and of Saxony; the king of Bohemia made the seventh of the group. Beside these states, the dominions of other rulers scarcely less important than the electors appear on the map. Some of these territories, like Würtemberg, Bavaria, Hesse, and Baden, are familiar to us to-day as members of the present German empire, but all of them have been much enlarged since the sixteenth century by the absorption of the little states that formerly lay within and about them.[264] [Sidenote: The towns.] The towns, which had grown up since the great economic revolution that had brought in commerce and the use of money in the thirteenth century, were centers of culture in the north of Europe, just as those of Italy were in the south. Nuremberg, the most beautiful of the German cities, still possesses a great part of the extraordinary buildings and works of art which it produced in the sixteenth century. Some of the towns held directly of the emperor, and were consequently independent of the particular prince within whose territory they were situated. These were called _free_, or _imperial_, cities and must be reckoned among the states of Germany. [Illustration: Wall of the formerly Free Town of Rothenburg] [Sidenote: The knights.] The knights, who ruled over the smallest of the German territories, had once formed an important military class, but the invention of gunpowder and of new methods of fighting had made their individual prowess of little avail. As their tiny realms were often too small to support them, they frequently turned to out-and-out robbery for a living. They hated the cities because the prosperous burghers were able to live in a luxurious comfort which the poor knights envied but could not imitate. They hated the princes because these were anxious to incorporate into their own territories the inconvenient little districts controlled by the knights, many of whom, like the free cities, held directly of the emperor, and were consequently practically independent. [Sidenote: Complexity of the map of Germany.]