Slangerup, earlier Slangir, was a royal residence from Viking times, perhaps as early as 1000. It was part residence, part farm, and enclosed so it could serve as a small fort. About 1095 King Erik Ejegod, who was born here, replaced the wooden stave church with a limestone church dedicated to Saint Nicholas. It was planned to be the largest church in Scandinavia and its final dimensions were 60 meters long and 13 meters wide. The church was later enlarged to comprise a nave with two side aisles and an apse added onto the choir. It also had double west towers about 30 meters in height. It is thought that Erik Ejegod was trying to establish the Hvide family's status by building such a massive church.
In 1170 King Valdemar I gave the "farm" and church of Slangerup to a community of Benedictine nuns, and the newly established abbey was dedicated to Our Lady and Saint Nicholas at the suggestion of Absalon, Bishop of Roskilde. The massive church had become costly to the royal family, and so it made economic sense to establish the nuns there and let others help pay for the complex. Valdemar moved his unmarried daughters to the abbey where they could be watched over and educated. The church became one wing of the enclosure that separated the nuns from the world. They had their own private entry to the choir of the church which was gated off from the rest of the congregation, who attended the church only on holy days.
In 1187 a letter was written to Bishop Absalon complaining that not all the nuns were "virtuous". This complaint led to the replacement of the Benedictine nuns with the new and strict Cistercian order, which was seen as a reforming rule. Most often a new Cistercian head of house and several Cistercian nuns were put in charge of the "unruly" house. Nuns either left or conformed to the rule.
Throughout the 1200s and 1300s the abbey received many rent properties and gifts of money from noble families for services rendered by the nuns for recently departed family members or for burial inside the Church. They also received donations and allowances from families who sent unmarried women to live a quasi-religious life in the nunnery until they married or took the vows of chastity, poverty, and obedience.
In 1311 King Erik Menved issued a decree of shame against the nuns for their unruly behavior.
By 1344 the reputation of the abbey must have improved again, because Princess Agnete of Sweden, the daughter of King Birger Magnusson, and her retinue were sent to live at Slangerup by Erik VII. To ensure the abbey's continued existence it was given the town of Slangerup and several other large properties. It is commemorated as a house for young unmarried women in the old Danish folk ballad "Sir Morten's Robbery" (Danish: Herr Mortens Klosterrov).
The Danish Reformation brought an end to the abbey at Slangerup. In 1529 the estate was given to Martin Bussert, the royal builder, who lost it during the Counts' Feud. All religious houses were closed and nunneries such as Slangerup Abbey were secularized in 1536. Women already in residence were allowed to continue to live in the former nunneries under the supervision of a secular prioress and prior. They essentially became homes for single women. Nobles were given use and income of the estate with the condition that they assume responsibility for the remaining nuns. At Slangerup this arrangement lasted until 1555 when Arild Ubbe was given the estate by Christian III. In 1559 the valuable estate and its rent properties were broken up and divided between Copenhagen Castle, the University of Copenhagen, and the town of Slangerup.
The very large St. Nicholas' church was adjudged superfluous and demolished in 1572; the materials were used to construct St. Michael's Church in Slangerup. Part of the altarpiece at St. Michael's includes the wooden altarpiece from Slangerup Abbey Church. By 1600 the entire monastic complex was completely demolished. The building materials were sold to Frederik II to be used in the construction of Frederiksborg Castle at Hillerød.
Several excavations have been made to determine the location of the church and abbey in Slangerup. After careful observations the sites were reburied; there are no visible remains of the abbey at Slangerup.
- Slangerup History Society: Slangerup Abbey (Danish)
- Slangerup Parish website: history of the abbey and church (Danish)