His court in Vienna became known as a centre of medieval Minnesang and he also played an important rule in the Empire's policies, acting as an arbitrator in the struggle between the Hohenstaufen emperor Frederick II and Pope Gregory IX.

Frederick's counsellor Archbishop Engelbert of Cologne had initially planned for a bride from the English royal Angevin dynasty, however, the attempt failed, as did Henry's former engagement with the Přemyslid princess Agnes, daughter of King Ottokar I of Bohemia.

In 1228, Henry took over the rule in the German kingdom and tried to limit the powers of the princes, thereby disturbing the Imperial policies of his father who made him pay homage under the threat of excommunication.

In 1246 Margaret's brother Duke Frederick II of Austria, last scion of the Babenberg dynasty, died childless in the Battle of the Leitha River, leaving a succession crisis.

As King Wenceslaus I of Bohemia wanted to take control over the duchies south of his realm, he arranged for the wedding of his eldest son and heir, Margrave Vladislaus III of Moravia, with Gertrude.

Ottokar acquired the imperial privileges sealed with a Golden Bull on the basis of the Privilegium Minus, acknowledged by Emperor Frederick II, which legitimized his claim over Austria and Styria, since Margaret was the heiress of the last duke by proximity of blood.

While Ottokar married Kunigunda of Halych, a grand-daughter of King Béla IV of Hungary, the repudiated Queen Margaret left Bohemia and returned to her Austrian homeland.

King Ottokar II kept Austria, Styria; he also acquired the Duchy of Carinthia with the March of Carniola in 1269, claiming to be the heir designated by Margaret in their divorce settlement.