King Ottokar II aspired to the crown of the Holy Roman Empire. His ambitions started the conflict with the House of Habsburg, which was, until then, composed of little-known counts, who suited the interests of German noble houses better than the mighty king Ottokar. The Habsburg representative, Rudolf, was elected as King of the Romans. In the Battle of Marchfeld (1278), Ottokar clashed with the Imperial and Hungarian armies, only to be killed. The Habsburgs then acquired Austria, retaining it until the 20th century.