The oldest Cistercian Monastery in the world has been in existence since 1129. Monks have lived and worked here constantly ever since it was endowed by Margrave Leopold I., the man who also founded Styria. The Monastery is 15 km north of Graz in a tributary valley of the River Mur at Gratwein. The first monks arrived here from Ebrach in Franconia. There are 17 monks today maintaining the living tradition in the Cistercian community of the Rein Monastery.

Monks from Rein established 4 affiliate monasteries. These off-shoots are Sittich in Slovenia 1138, Wilhering near Linz 1146, the Neukloster Monastery in Wiener Neustadt 1444 and Schlierbach in Upper Austria 1620. The Cistercians were first and foremost skilled artisans, their hard labour turned the surrounding land into fertile fields and they planted fruitful vineyards on the mountainsides. The Great Scriptorium at Rein – where the monks wrote and copied manuscripts – can be compared in its significance for the times with a major publishing operation today. In addition to all of their practical tasks, the monks ministered as priests in pastoral work for the many parishes in the surrounding area.

As a foundation of the local rulers, Rein had a full share in the eventful history of Styria over the centuries. On a first glance Rein has the appearance of a typical Austrian baroque monastery. Recent renovation work, however, has uncovered wonderful architectural finds from the Gothic, Romanic and Roman periods. These earlier elements include the tomb of the founder Leopold I., which is shown to visitors on every guided tour of the Monastery.