The Queen Dowager Regent Hedwig Eleonora bought the castle in 1661, a year after her role as Queen of Sweden ended, but it burnt to the ground on 30 December that same year. Hedwig Eleonora engaged the architect Nicodemus Tessin the Elder to design and rebuild the castle. In 1662, work began on the reconstruction of the building. With the castle almost complete, Nicodemus died in 1681. His son Nicodemus Tessin the Younger continued his work and completed the elaborate interior designs. The Flemish sculptor Nicolaes Millich made for the great staircase and hall sculptures of the nine muses in marble, along with a series of busts of Gothic kings. In addition, he also made bust portraits of King Charles X Gustav, his wife Hedwig Eleonor and both their sons, the young King Charles XI, probably also of Magnus Gabriel De la Gardie and his wife Maria Euphrosyne, a sister of King Charles X Gustav. Millich and his assistant Burchard Precht also made decorative wood carvings in the queen dowager's bed chamber.