At the beginning of the twelfth century, the entire Upper Savinja Valley was a large landholding of the Bavarian Diepold de Chagere, centred in Gornji Grad (Ger. Oberburg). In 1140, he donated it for the establishment of a Benedictine monastery, while a smaller part was handed over to Aquileia. During its 333 years of existence and extensive colonization, the monastery formed a cultural landscape with approximately 750 farms and market towns of Gornji Grad, Ljubno (Ger. Laufen) and Rečica (Ger. Rietz). The Aquileian estates with the castles of Gornji Grad, Vrbovec (Ger. Altenburg) and Mozirje (Ger. Prassberg) were fiefs in the hands of local families from the end of the thirteenth century. The most influential political forces were the Counts of Heunburg and the Lords of Sanneck. In 1286, the Heunburg family, with their seat in Mozirje, also became hereditary advocates of the Benedictine abbey. After their extinction in 1322, they were succeeded by the Sannecks (from 1341, the Counts of Cilli). The monastery was incorporated into the newly established diocese of Ljubljana in 1461 and abolished in 1473. Gornji Grad continued to flourish as the secondary residence of the bishop of Ljubljana.