The origins of the monastery are unknown. According to legend, the monastery was founded in the 12th century by two sisters of the aristocratic family Schlossberg (in later tradition called Schlüsselberg), whose castle was nearby, and called in Cella Dei, rendering Gottes Zelle in German. Already in 1238, the refounded abbey was officially recognised by Pope Gregory IX who also put it under the spiritual supervision of Salem Abbey which lasted until 1753 when the task was transferred to Kaisheim Abbey. A fire in 1522 caused considerable damage, destroying the cloister.