But, although Rudolf had so readily given up all for which the Hohenstaufens had struggled in Italy, he at once claimed their estates in Germany as belonging to the crown. This brought him into conflict with Counts Ulric and Eberhard II. of Würtemberg, who were also allied with king Ottokar II. of Bohemia in opposition to his authority. The latter had obtained possession of Austria, through marriage, and of all Styria and Carinthia to the Adriatic by purchase. He was ambitious and defiant: some historians suppose that he hoped to make himself Emperor of Germany, others that his object was to establish a powerful Slavonic nation. Rudolf did not delay long in declaring him outlawed, and in calling upon the other princes for an army to lead against him. The call was received with indifference: no one feared the new Emperor, and hence no one obeyed. [Sidenote: 1278.] Gathering together such troops as his son-in-law, Ludwig of the Bavarian Palatinate, could furnish, Rudolf marched into Austria, after he had restored order in Würtemberg. A revolt of the Austrian and Styrian nobles against Bohemian rule followed this movement: the country was gradually reconquered, and Vienna, after a siege of five weeks, fell into Rudolf's hands. Ottokar II. then found it advisable to make peace with the man whom he had styled "a poor Count," by giving up his claim to Austria, Styria and Carinthia, and paying homage to the Emperor of Germany. In October, 1276, the treaty was concluded. Ottokar appeared in all the splendor he could command, and was received by Rudolf in a costume not very different from that of a common soldier. "The Bohemian king has often laughed at my gray coat," he said; "but now my coat shall laugh at him." Ottokar was enraged at what he considered an insulting humiliation, and secretly plotted revenge. For nearly two years he intrigued with the States of Northern Germany and the Poles, collected a large army under the pretext of conquering Hungary, and suddenly declared war against Rudolf.