Following the death of Frederick II the Quarrelsome in 1246 without heirs, Austria entered a period of instability known as the Interregnum. This time of competing claims and power struggles marked the end of the Babenberg dynasty and left the duchy vulnerable to foreign ambitions.
The Privilegium Minus of 1156 allowed Austria to be inherited through female lines, prompting multiple claimants to pursue the duchy. Vladislaus of Moravia, son of King Wenceslaus I of Bohemia, married Gertrud, Frederick’s niece, positioning himself as a potential successor. However, Vladislaus died in 1247 before securing control, and his claim was followed by Herman of Baden, another suitor of Gertrud, though he also failed to gain support.
In 1251, Austrian nobles, tired of the power struggle, invited Ottokar II Přemysl of Bohemia, Vladislaus' brother, to take control of Austria. Ottokar solidified his claim by marrying Margaret of Babenberg, Frederick’s sister, in 1252, connecting himself to the former ruling dynasty. He quickly subdued the rebellious Austrian nobility, taking control of Austria, Styria, Carinthia, and Carniola, laying the foundation for a vast central European realm.
Ottokar’s Rule and Ambitions
Ottokar II was both a skilled administrator and a builder. He founded the Hofburg Palace in Vienna and aimed to establish a powerful new empire during the ongoing imperial interregnum that followed the death of Frederick II of the Holy Roman Empire in 1250. With the weakening of the empire, Ottokar advanced his candidacy for the imperial throne but was ultimately unsuccessful.
During this period, Austria also became a center of religious persecution, as the Inquisition targeted Waldensians and other heretical groups, especially in the Danube region between the Salzkammergut and the Vienna Woods.
Rise of Rudolf of Habsburg and Ottokar’s Downfall
In 1273, the imperial throne was filled by Rudolf of Habsburg, who was determined to consolidate imperial authority. Ottokar II refused to recognize Rudolf’s election, leading to conflict. In 1274, the Imperial Diet in Nuremberg demanded that all crown lands seized since 1250, including Austria, be returned to the empire. Ottokar resisted, holding on to Austria, Styria, Carinthia, and Carniola, which he had taken during the Babenberg succession dispute.
In 1276, Rudolf declared war on Ottokar, laying siege to Vienna and forcing him to cede the disputed territories. Ottokar was allowed to retain the Kingdom of Bohemia and betroth his son, Wenceslaus II, to Rudolf’s daughter Judith of Habsburg. However, tensions persisted, and Ottokar soon sought alliances with Polish nobles and German princes, including Henry XIII of Bavaria.
Battle of the Marchfeld and the Habsburg Victory (1278)
On August 26, 1278, the decisive Battle of the Marchfeld took place northeast of Vienna. Rudolf, with support from King Ladislaus IV of Hungary, defeated and killed Ottokar II. The victory secured Rudolf’s control over Austria, Styria, and the surrounding regions.
With Ottokar’s death, the Margraviate of Moravia fell under Habsburg administration, and Ottokar’s widow, Kunigunda of Slavonia, retained only limited authority around Prague. Wenceslaus II was re-betrothed to Judith of Habsburg, ensuring peace between Bohemia and the Habsburgs.
Habsburg Dynasty Takes Root (1278–1282)
Following his victory, Rudolf of Habsburg assumed the titles of Duke of Austria and Styria, marking the beginning of over six centuries of Habsburg rule in Austria, which would last until 1918. This victory not only ended the interregnum but also laid the foundation for the Habsburgs' rise to dominance in Central Europe.