Rudolph derived considerable support from his sons-in-law the Electors of Palatine and Saxony, and from the Elector of Brandenburg; the Burgrave of Nuremberg, the nobles of Alsace and Swabia, and the citizens and mountaineers of Switzerland.  Having made the necessary preparations, he, with a judicious policy, turned his attention to those princes who, from the vicinity of their dominions, were in a state of continual enmity or warfare with the King of Bohemia.  He concluded a treaty with Ladislaus, King of Hungary, and strengthened the bond of union by betrothing his daughter to Andrew, Duke of Slavonia and brother of Ladislaus.  He entered into an alliance with Meinhard, Count of Tyrol, which he cemented by the marriage of his eldest son Albert with Elizabeth, daughter of Meinhard.  But his views were still more promoted by the general discontent which pervaded every part of the Austrian dominions, and by the anathemas of Philip, titular Duke of Carinthia and Archbishop of Salzburg, who absolved the people of his diocese from their oath of allegiance, and exhorted them to shake off the yoke of a tyrant and receive the chief of the empire.

The prelate made repeated exhortations to Rudolph to hasten his expedition.  He drew a hideous picture of Ottocar’s oppressions; expatiated on the discontents of the natives, and their inveterate hatred to the Bohemians, and used all his eloquence to encourage the King of the Romans to invade the country.  “I observe,” he says, “the countenances of your adversaries pale with terror; their strength is withered; they fear you unknown; your image is terrible in their imaginations; and they tremble even at the very mention of your name.  How will they act, and how will they tremble when they hear the voice of the approaching thunder, when they see the imperial eagles rushing down on them like the flash of the lightning!”

The plan formed by Rudolph for the prosecution of the war was calculated to divide the forces and distract the attention of Ottocar.  He himself was to penetrate into Bohemia, while his son was to invade Austria, and Meinhard of Tyrol to make a diversion on the side of Styria.  To oppose this threatened invasion, Ottocar assembled a considerable army, sent a reenforcement to Henry of Bavaria, augmented the garrison of Klosterneuburg, a fortress deemed impregnable, fortified Vienna, and despatched a considerable party of his army toward Teppel to secure his frontier; but resigning himself to supineness and careless security, he passed that time, which should have been employed in repressing the discontented by his presence and rousing the courage of his troops, in hunting and courtly diversions.