Klosterneuburg Priory (German: Stift Klosterneuburg) is a Roman Catholic monastery of Augustinian Canons in the Lower Austrian town of Klosterneuburg on the Danube river, just north of the Vienna city limits at the Leopoldsberg.
It was founded in 1114 by the Austrian margrave Saint Leopold III, a Babenberger and the patron saint of Austria, and his second wife Agnes, a daughter of the Imperial Salian dynasty. According to legend, a gust out of the clear sky carried away Agnes' veil; her husband retrieved it years later and decided to build the monastery at the location. In fact Margrave Leopold had taken his residence at Neuburg ("Newcastle") and aimed to establish a separate Austrian diocese here, which met with strong opposition by the Bishops of Passau. Nevertheless the foundation is one of the oldest and richest of its kind in Austria and owned much of the land of the nowadays north-western suburbs of Vienna. Leopold's younger son, the chronicler Otto of Freising prepared for his ecclesiastical career at Klosterneuburg and became provost in 1126. The canons turned to the Augustinian rule in 1133.
The impressive building complex, the greater part of which was constructed between 1730 and 1834, stands on a hill rising directly from the banks of the Danube. Its foundations, including a castle tower and a Gothic chapel date back to the 12th century. Other older buildings still extant within the complex include the chapel of 1318 with Saint Leopold's tomb. From 1634 on the Habsburg rulers had the facilities rebuilt in a Baroque style, continued by the architects Jakob Prandtauer, Joseph Emanuel Fischer von Erlach and Donato Felice d'Allio. The plans to embellish the monastery on the scale of an Austrian Escorial were later resumed by the Neoclassical architect Joseph Kornhäusel, though only small parts were actually carried out. From 1882 on the priory church was restored according to plans by Friedrich von Schmidt, whereby the Neo-Gothic twin steeples were attached.
The monastery premises also include a treasury with the Austrian archducal hat made on the behest of Archduke Maximilian III of Habsburg, a relic-chamber, and a library with 30,000 volumes and many manuscripts. It has also a centuries-long viticultural tradition and owns one of the largest wineries in Austria. The wine cellar contains an immense tunnel similar to the one at Heidelberg Castle.
The chapel of St Leopold contains the Verdun Altar made in 1181 by Nicholas of Verdun. Its three parts comprise 45 gilded copper plates modeled on Byzantine paragons, similar to the Shrine of the Three Kings at Cologne Cathedral. Originally manufactured as panels, they were assembled as an altar in secondary utilization circa 1330.
The tripartite concept is reflected in the arrangement of the plates. According to the biblical exegesis, the depictions are split into three rows of the eras of Adam and Noah, of Abraham, David and the Babylonian captivity and finally of Jesus' life, placed in the central part. The columns of adjacent plates of different ages symbolise their connection according to the ideas of the typology theory. The arrangement may refer to the mystic doctrines of the medieval theologian Hugh of Saint Victor.