[Sidenote: 1256.] Inasmuch as the German Order really owed its existence to the support of the merchants of the Northern coast, Hermann of Salza sought for a field of labor wherein the knights might fulfil their vows, and at the same time achieve some advantage for their benefactors. As early as 1199, the Bremen merchants had founded Riga, taken possession of the eastern shore of the Baltic and established German colonies there. The native Finnish or Lithuanian inhabitants were either exterminated or forcibly converted to Christianity, and an order, called "the Brothers of the Sword," was established for the defence of the colonies. This new German territory was separated from the rest of the Empire by the country between the mouths of the Vistula and the Memel, claimed by Poland, and inhabited by the Borussii, or _Prussians_, a tribe which seems to have been of mixed Slavic and Lithuanian blood. Hermann of Salza obtained from Poland the permission to possess this country for the German Order, and he gradually conquered or converted the native Prussians. In the meantime the Brothers of the Sword were so hard pressed by a revolt of the Livonians that they united themselves with the German Order, and thenceforth formed a branch of it. The result of this union was that the whole coast of the Baltic, from Holstein to the Gulf of Finland, was secured to Germany, and became civilized and Christian. During the thirty-five years of Frederick II.'s reign and the seventeen succeeding years of the Interregnum, Germany was in a condition which allowed the strong to make themselves stronger, yet left the weaker classes without any protection. The reigning Dukes and Archbishops were, of course, satisfied with this state of affairs; the independent counts and barons with large possessions maintained their power by temporary alliances; the inferior nobles, left to themselves, became robbers of land, and highwaymen. With the introduction of new arts and the wider extension of commerce, the cities of Germany had risen in wealth and power, and were beginning to develop an intelligent middle-class, standing between the farmers, who had sunk almost into the condition of serfs, and the lesser nobles, most of whom were equally poor and proud. Upwards of sixty cities were free municipalities, belonging to the Empire on the same terms as the dukedoms; that is, they contributed a certain proportion of men and money, and were bound to obey the decrees of the Imperial Diets. [Sidenote: 1256. ROBBER-KNIGHTS.--CITIES.]