Rudolph was crowned in
Aachen Cathedral on
24 October 1273. Friedrich Schiller in
Der Graf von Habsburg ("The Count of Habsburg") presents a fictionalized rendering of the feast King Rudolf held following his coronation. To win the approbation of the Pope, Rudolph renounced all imperial rights in
Rome, the
papal territory, and
Sicily, and promised to lead a new
crusade. Pope Gregory X, in spite of Otakar's protests, not only recognized Rudolph himself, but persuaded
Alfonso X, King of Castile (another grandson of
Philip of Swabia), who had been chosen German king in 1257 as the successor to
William of Holland, to do the same. Thus, Rudolph surpassed the two heirs of the Hohenstaufen dynasty that he had earlier served so loyally.
In November 1274 it was decided by the
Diet of the Realm in Nuremberg that all crown estates seized since the death of the Emperor Frederick II must be restored, and that
Otakar must answer to the Diet for not recognizing the new king. Otakar refused to appear or to restore the provinces of
Austria, Styria, Carinthia and
Carniola, which he had claimed through his first wife, a
Babenberg heiress, and which he had seized while disputing them with another Babenberg heir,
Hermann VI, Margrave of Baden. Rudolf refuted Otakar's succession to the Babenberg patrimony, declaring that the provinces reverted to the crown due to the lack of male-line heirs (a position that conflicted with the provisions of
Privilegium Minus). King Otakar was placed under the state ban; and in June 1276 war was declared against him. Having persuaded Otakar's ally
Henry I, Duke of Lower Bavaria, to switch sides, Rudolph compelled the Bohemian king to cede the four provinces to the control of the royal administration in November 1276. Rudolf then invested Otakar with Bohemia, betrothed one of his daughters to Otakar's son
Wenceslaus, and made a triumphal entry into
Vienna. Otakar, however, raised questions about the execution of the treaty, made an alliance with some
Polish chiefs, and procured the support of several German princes, including his former ally, Henry of Lower Bavaria. To meet this coalition, Rudolph formed an alliance with
Ladislaus IV, King of Hungary, and gave additional privileges to the citizens of Vienna. On
26 August 1278 the rival armies met on the banks of the
River March in the
Battle of Dürnkrut and Jedenspeigen where Otakar was defeated and killed.
Moravia was subdued and its government entrusted to Rudolph's representatives, leaving
Kunigunda, the Queen Regent of Bohemia, in control of only the province surrounding Prague, while the young Wenceslaus was again betrothed to one of Rudolf's daughters.
Rudolph's attention next turned to the possessions in Austria and the adjacent provinces, which were taken into the royal domain. He spent several years establishing his authority there but found some difficulty in establishing his family as successors to the rule of those provinces. At length the hostility of the princes was overcome. In December 1282, in
Augsburg, Rudolph invested his sons,
Albert and
Rudolph, with the duchies of Austria and Styria and so laid the foundation of the House of Habsburg. Additionally, he made the twelve-year-old Rudolf Duke of
Swabia, which had been without a ruler since Conradin's execution. The 27-year-old Duke Albert (married since 1274 to a daughter of Count
Meinhard II of Tirol (1238-95)) was capable enough to hold some sway in the new patrimony.
In 1286 King Rudolf fully invested the
Duchy of Carinthia, one of the provinces conquered from Otakar, to Albert's father-in-law
Meinhard. The princes of the realm did not allow Rudolf to give everything that was recovered to the royal domain to his own sons, and his allies needed their rewards too.
Turning to the west, in 1281 he compelled
Philip, Count Palatine of Burgundy, to cede some territory to him, then forced the citizens of
Bern to pay the tribute that they had been refusing, and in 1289 marched against Philip's successor,
Otto IV, compelling him to do homage.
In 1281 his first wife died. On
5 February 1284 he married Isabella, daughter of
Hugh IV, Duke of Burgundy, his western neighbor.
Rudolph was not very successful in restoring internal peace to Germany. Orders were indeed issued for the establishment of landpeaces in
Bavaria, Franconia and
Swabia, and afterwards for the whole of Germany. But the king lacked the power, resources, or determination, to enforce them, although in December 1289 he led an expedition into
Thuringia where he destroyed a number of
robber-castles.
In 1291 he attempted to secure the election of his son Albert as German king. However, the princes refused claiming inability to support two kings, but in reality, perhaps, leery of the increasing power of the Habsburgs.
