There is a legend that it was originally founded in the Carolingian period, in about 750, by Saint Lioba, and it is true that a few traces of architecture from that period survive. However, firm information is available only from the 11th century, when the monastery, with some property to endow it, was given by Counts Ludwig and Beringer of Sangershausen to Hirsau Abbey, against the background of the Investiture Controversy and the Hirsau Reforms. It was duly re-founded as a priory of Hirsau.
The Vögte (or lay stewards) were the Counts of Rieneck, kin of the founders, who persistently over the next centuries tried to acquire the property for themselves. Eventually, after severe damages sustained during the Peasants' War, the then Abbot of Hirsau dissolved the monastery at Schönrain and sold the premises to the Rienecks, who re-built it as a residence.
The site, after a number of descents, passed to the Bishops of Würzburg, who used it as accommodation for their forestry officials. It was secularised in 1802 and continued in use by the forestry officials of the Kingdom of Bavaria. When their headquarters was moved elsewhere, the buildings at Schönrain were re-used for building materials, and the site has been in ruins since that time.
Since 1973 the site and the ruins have been under the protection of a local environmental and historical preservation group, the Lohrer Heimatfreunde.