The abbey's property was confiscated in 1527 in accordance with the Reduction of Gustav I of Sweden, and the abbey buildings were burned by Danish forces 1566 during the Northern Seven Years' War. In the middle of the 17th century, Magnus Gabriel De la Gardie received the abbey as a gift from the Swedish queen Christina. De la Gardie restored the church and established a family mausoleum in it, while the remaining abbey buildings were left to decay. The church was thoroughly restored 1911–1923. Archeological excavations of the central part of the abbey were made 1921–1929, and again 1976 and 1977. In May 2002, the grave of Birger jarl was opened. The scientific analysis that followed, strengthened the belief that the three skeletons in the grave are the remains of Birger jarl, his son duke Eric Birgersson and Birger's wife Mechtild of Holstein.