But the question, in the meantime, was assuming a new aspect. Rudolf’s alarm at the opposition of Ottakar, and his desire to secure all the Imperial rights, were combining with other circumstances to induce him to put forward a claim for the restoration to the Empire of the Duchies of Austria, Styria, Carniola, and Carinthia. Ottakar had been unwilling to resist the pressure of the Pope and the advice of Bruno; but he now demanded that, before doing homage to Rudolf, he should have a clear guarantee for the possession of the lands that he had conquered.
In his determination to resist the demands of Rudolf, Ottakar seems to have been strangely unaware of the dangers that were surrounding him. Rudolf was, in the meantime, making allies with great sagacity. Count Meinhard of the Tyrol had been the Count of Hapsburg’s most intimate friend; and he was one of the many who looked with jealous eyes on Ottakar’s possession of Carinthia. The Archbishop of Salzburg had claimed some rights in Styria, and was besides continually harassed by encroachments on the part of Ottakar; Henry of Bavaria had been one of those to whom the nobles of Styria had offered their dukedom; and though his friendship for Ottakar shows that he must have abandoned this claim for a time, the offer of one of Rudolf’s useful daughters finally detached him from his alliance with Bohemia.
In the meantime, the indefatigable Burggraf of Nürnberg had discovered and fomented the discontents of the nobles of Austria and Styria; and he announced to Ottakar that the Ban of the Empire had been proclaimed against him. But even now Ottakar was unaware of Rudolf’s plans; he probably despised his military ability; and he thought it sufficient to send a small force to the defence of the Bohemian frontier, while he gave himself up to hunting and other amusements. He was, therefore, terribly startled when, in September, 1276, Rudolf suddenly entered Austria. Almost at the same time Count Meinhard invaded Carinthia, and the Styrian nobles, rising in insurrection, drove out Milota from their country. Still Ottakar hoped to save himself by the devotion of the towns; for six months, Vienna justified his expectations by holding out against Rudolf’s army; and Paltram, the Burgomaster, roused the citizens to a vigorous defence on behalf of the King, who had showed them such favour. Ottakar, now stirred to action, marched into Austria and occupied one side of the Danube; from whence he hoped to make an attack on the rear of Rudolf’s army. But the Count Palatine of the Rhine hastened to seize the fortresses which lay between him and the German army; and it was now that Ottakar became thoroughly aware of the defection of his nobles. Fortress after fortress surrendered to Rudolf without a struggle; and at last the poorer men in Vienna, seeing the continual destruction of their vineyards outside the city, called upon Paltram to surrender. He, finding that Ottakar did not arrive, despaired of holding out longer; though, before surrendering, he exacted from Rudolf a promise that he would maintain the liberties of Vienna.