In the tenth century Austria, with both Styria and Carniola, under the title of a margravate, was governed by Leopold I of the house of Bamberg.  It continued in the possession of his family, and in 1156 was erected into an independent duchy by the emperor Frederick II, and conferred on Henry, fifth in descent from Leopold, as an indivisible and inalienable fief; in failure of male issue it was made descendible to his eldest daughter, and, in failure of female issue, disposable by will.  In 1245 Frederick the Warlike, last duke of the Bamberg line, obtained a confirmation of this decree; but, dying in the ensuing year without issue and without disposing of his territories by will, a dispute arose relative to his succession.  The claimants were his two sisters, Margaret, widow of Henry VII, King of the Romans, and Constantia, wife of Henry the Illustrious, Margrave of Misnia; and his niece Gertrude, daughter of Henry, his elder brother, the wife of Premislaus, eldest son of Wenceslaus, King of Bohemia and brother of Ottocar.  But on the plea that neither of the claimants was a daughter of the last Duke, the Emperor Frederick II sequestrated these territories as fiefs escheating to the empire, and transferred the administration to Otho, Count of Werdenberg, who took possession of the country and resided in Vienna.

As this event happened during the contest between the see of Rome and the house of Swabia, Innocent IV, who had deposed and excommunicated Frederick, laid Austria under an interdict, and encouraged the kings of Bohemia and Hungary and the Duke of Bavaria to invade the country.  The Pope first patronized the claims of Margaret, and urged her to marry a German prince; but on her application to the Emperor to bestow the duchy on her eldest son Frederick, he supported Gertrude, who, after the death of Premislaus, had espoused Herman, Margrave of Baden, nephew of Otho, Duke of Bavaria, and induced the anticaesar, William of Holland, to grant him the investiture.

On the demise of Frederick II his son Conrad was too much occupied with the affairs of Italy to attend to those of Germany; the imperial troops quitted Austria, and, Herman dying, Otho of Bavaria occupied that part of Austria which lies above the Ems.  But Wenceslaus of Bohemia, prevailing on the states to choose his eldest surviving son Ottocar as their sovereign, under the condition that he should espouse Margaret, expelled the Bavarians and took possession of the whole country.  Gertrude fled to Bela, King of Hungary, whose uncle Roman, a Russian prince, she married, and ceded to him her pretensions on Styria, on condition that he should assert her right to Austria.  A war ensued between Ottocar and the King of Hungary, in which Ottocar, being defeated, was compelled to cede part of Styria to Stephen, son of Bela, and a small district of that country was appropriated for the maintenance of Gertrude.  But the Hungarian governors being guilty of the most enormous exactions the natives of Styria rose and transferred