Originally a Swabian count, he was the first Habsburg to acquire the duchies of Austria and Styria in opposition to his mighty rival, the Přemyslid king Ottokar II of Bohemia, whom he defeated in the 1278 Battle on the Marchfeld.

At his father's death in 1239, Rudolf inherited from him large estates around the ancestral seat of Habsburg Castle in the Aargau region of present-day Switzerland as well as in Alsace.

Thus, in 1240,[3] in order to quell the rising power of Rudolf and in an attempt to place the important "Devil's Bridge" (Teufelsbrücke) across the Schöllenenschlucht under his direct control, Emperor Frederick II granted Schwyz Reichsfreiheit in the Freibrief von Faenza.

As the day passed on,[clarification needed] Count Rudolf bribed the sentinels of the city and gained entry, killing Hugh in the process.

Then in 1244, to help control Lake Lucerne and restrict the neighboring forest communities of Uri, Schwyz and Unterwalden, Rudolf built near its shores Neuhabsburg Castle.

He received as her dowry the castles of Oettingen, the valley of Weile, and other places in Alsace, and he became an important vassal in Swabia, the former Alemannic German stem duchy.

When night fell, he penetrated the suburbs of Basle and burnt down the local nunnery, an act for which Pope Innocent IV excommunicated him and all parties involved.

Successful feuds with the Bishops of Strasbourg and Basel further augmented his wealth and reputation, including rights over various tracts of land that he purchased from abbots and others.

These various sources of wealth and influence rendered Rudolf the most powerful prince and noble in southwestern Germany (where the tribal Duchy of Swabia had disintegrated, enabling its vassals to become completely independent).

Rudolf's election in Frankfurt on 1 October 1273,[4] when he was 55 years old, was largely due to the efforts of his brother-in-law, the Hohenzollern burgrave Frederick III of Nuremberg.

Rudolf refused to accept Ottokar's succession to the Babenberg patrimony, declaring that the provinces reverted to the Imperial crown due to the lack of male-line heirs.

Having persuaded Ottokar's former ally Duke Henry XIII of Lower Bavaria to switch sides, Rudolf compelled the Bohemian king to cede the four provinces to the control of the royal administration in November 1276.

Ottokar, however, raised questions about the execution of the treaty, and procured the support of several German princes, again including Henry XIII of Lower Bavaria.

To meet this coalition, Rudolf formed an alliance with King Ladislaus IV of Hungary and gave additional privileges to the Viennese citizens.

But the king lacked the power, resources, and determination to enforce them, although in December 1289 he led an expedition into Thuringia, where he destroyed a number of robber castles.

Fourteen years after his death a ransom was paid for his body by Alexander ben Shlomo (Susskind) Wimpfen, who was subsequently laid to rest beside the Maharam.