The Schaunbergers, who are descended from lords of Julbach (am Inn), were granted the lucrative imperial fief of Aschach an der Donau by Kaiser Friedrich Barbarossa in the middle of the 12th century.

Over the course of the 13th century the Schaunbergers built up a Vogtei (bailiwick), particularly by means of high jurisdiction, (over the Cistercian Wilhering Abbey) and church patronage, mainly between Kürnberg, Sauwald, the Danube and Hausruck.

Documents from 1316 already refer to the Schaunbergers as Grafen (counts), and speak of the territory as "terra nostra"; it was a Grafschaft (county) with a Landrecht and a special position in Upper Austria.

With the succession of the Austrian Habsburgs to the imperial throne (Friedrich III and then Maximilian I), the special rights of the Schaunergers were finally curtailed; in 1548 during the Reformation the Schaunbergers lost their voting rights in the Imperial Diet upon becoming Lutheran, and in 1559 the male line died out upon the death of Count Wolfgang von Schaunberg, after which the title was inherited by the Starhembergers through his sister Anna.

After the extinction of the male line of Schaunbergers, the fief was, through a compromise with Kaiser Maximilian II on 10 August 1572, mortgaged to the Starhembergs and the Liechtensteiners, requiring 45,000 florins for repayment, and ceding of the district court and Wildbannforst in the Danube Valley.