The Régence style Blumenstein manor house was built in 1725-1728 for the governor Franz Heinrich von Stäffis-Mollondin in the center of a 20 hectares terraced park. After Franz Heinrich's death in 1749 the estate passed to his son Joseph Lorenz von Stäffis-Mollondin. When Joseph died in 1758 without an heir the Stäffis-Mollondin family ended and the estate was divided between his daughters Johanna Karolina Anophe and Ludovika Franziska, their grandmother Jeanne Charlotte Cléophe and their mother Marie Jeanne Nicole. In 1797 Ludovika Franziska married Robert Fidel Carl Wallier von St. Aubin and the entire estate passed to the von St. Aubin family. In 1847 Ludovika Franziska died and Blumenstein passed to her sister in law Charlotte Glutz-Wallier von St. Aubin. About a decade later, in 1856, her sons Edmund, Ludwig and Alfred Glutz-Ruchti inherited the house. In 1861 Edmund bought out his brothers shares and became the only owner of Blumestein.
Edmund Glutz-Ruchti bequeathed Blumenstein in 1885 to his nephew Joseph Glutz-Ruchti. Over next decades Joseph modernized the old building and installed central heating which changed it from a summer residence into a home that was comfortable year round. He supported the renovations and lavish lifestyle by selling the furnishings and the lands around the estate. However, by the mid-1920s he was insolvent. When Joseph went bankrupt, Blumenstein was sold at auction. On 18 October 1928, the Basel architect HR Steuer bought the empty castle and the remaining garden for 400,000 Francs. The garden was divided into lots and sold as building land.
The main building and the land immediately around the building were purchased on 11 September 1933 by Fritz Hirt-Baumgartner for 85,000 francs. Over the following two decades Fritz Hirt-Baumgartner and his wife Lucie attempted to buy back all the furnishings and outbuildings from Blumenstein.
On 7 February 1951 the couple sold Blumenstein for CHF 180,000 along with its inventory for CHF 40,000 to the municipality of Solothurn. The Blumenstein Museum or Historical Museum of Solothurn opened on 3 May 1952. Fritz Hirt-Baumgartner's wife Lucie retained the right to reside in several rooms of the upper floor until her death in 1977.
Today the museum is open from Tuesday to Sunday. Admission is free and some rooms are available to rent for parties and meetings.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.