The Margraviate of Austria flourished under the rule of Leopold III (Leopold the Good was Margrave from 1095 to 1136. In 1485 he was canonized and became Saint Leopold III, patron saint of Austria & Vienna). Leopold the Good commissioned the construction of churches & abbeys, promoted the creation of new towns & permitted a great level of autonomy that helped Vienna become an important trade center during the 11th century.
In 1136 Leopold IV inherits the Margraviate of Austria & the following year he sets in motion the exchange of the Romanesque Church that would later become St. Peter’s Church (Peterskirche) which was given to the Bishop of Passau in return for extended stretches of land outside the city walls. Five years later, Leopold IV’s brother Henry II Jasomirgott, takes his place as Margrave of Austria & Duke of Bavaria after Leopold’s unexpected death & he moves his residence in Vienna soon after (1145). Two years later the most important religious building in Vienna to this day, St.Stephen’s Cathedral (Stephansdom) is consecrated, taking the place of the most important city symbol, a symbol of its growing importance as an imperial capital.
Henry II needed a big monastery for his new capital as in those days monasteries were mainly repositories of knowledge that could help the rulers in their administrative duties, so he founded the Roman Catholic Schottenstift (Scottish Abbey) Monastery in 1155.
In 1156 the newly elected Emperor Frederick I (Barbarossa) in an attempt to appease the unrest between his vassal princes & avoid the impeding civil war decides to return the Duchy of Bavaria to its last rulers from the House of Welfs & in the same time, in order to compensate the House of Babenberg for its loss, elevates the Margraviate of Austria into a duchy, administratively independent from Bavaria. The document issued by the Emperor known as Privilegium Minus turned out to be founding act of what was to become a nation. The year (1156) is sometimes given as Austria’s date of independence.