St. Emmeram's Abbey, now known as Schloss Thurn und Taxis and St. Emmeram's Basilica, was a Benedictine monastery founded in about 739 in Regensburg in Bavaria at the grave of the itinerant Frankish bishop Saint Emmeram. In 1295 the counter-king Adolf of Nassau granted the abbey the regalia and made it an Imperial abbey, an independent sovereign power subject directly to the emperor. In 1731, the abbots were raised to the status of Princes of the Empire (Reichsfürsten). Between 1731 and 1733 there followed the magnificent Baroque refurbishment, by the Asam brothers, of the abbey church, which had been repeatedly burnt out and repaired. In 1803, St. Emmeram's, along with the Imperial City of Regensburg, the Bishopric of Regensburg and the two other Imperial Abbeys (Niedermünster and Obermünster), lost its previous politically-independent status to the newly formed Principality of Regensburg, often referred to as the Archbishopric of Regensburg, under the former Prince-Primate Carl Theodor von Dalberg. After the Treaty of Paris of 1810, the entire Principality of Regensburg was transferred to Bavaria.
In 1812 the monastic buildings were granted to the Princes of Thurn and Taxis, who had St. Emmeram's Abbey converted as a residence known from then on as Schloss Thurn und Taxis, sometimes called Schloss Sankt Emmeram. Since 1834 the Gruftkapelle (Crypt Chapel) is the final resting place for the members of the nobles of Thurn und Taxis.