Already in the year 1076/79 a chapel in honor of St. Martin of Tours was consecrated on the Fürstenberg by the Cologne archbishop Hildolf. In 1116, Archbishop Frederick I of Schwarzenburg transferred the chapel to the Benedictine Abbey of Siegburg. On the advice of Norbert von Xantens, Heinrich von Darnick gave the convent a fief on the Fürstenberg on the condition that they should build a monastery there. Frederick I documented this donation in 1119; the donation of two farms in Birten and Eger, a property in Xanten and land in the now belonging to Wesel villages Werrich and Büderich Archbishop Arnold I of Cologne in 1144. At this time was on the Fürstenberg already the monastery of St. Mary a three-nave Romanesque abbey church with four towers. Since the deed of donation was used by both male and female members of the order, this monastery is believed to have been a double monastery since its founding. At the beginning of the 13th century, however, the male members of the Order left Fürstenberg and a women's monastery was built.
In 1259, the monastery was sold to the Cistercian order against the wishes of the Benedictine nuns living there, whose convent in Horst aan de Maas had been destroyed in a fire six years earlier. Archbishop Konrad von Hochstaden approved the rewriting on 7 August 1259, with the proviso that the remaining Benedictine nuns should continue to receive their support, but in return they were not allowed to receive any other members of the order. The archbishop of Utrecht had meanwhile built a new monastery in Honepa near Deventer as a replacement for the Cistercian monastery burned down in 1253, so that some of the religious returned there. Finally, in 1284, the last service of the Benedictine nuns took place at Fürstenberg Abbey, which was placed in 1265 under the protection of the provost of the Xanten Viktorstift.
Source: Wikipedia.de