The Château de By is a town museum run by the town of Thomery. The building was purchased in 1859 by the French animal painter Rosa Bonheur, who moved her studio there. Aged 37, she was at the height of her popularity and made the building her home and studio for forty years, with pens for her animals in its park. She rebuilt the chateau to make it comfortable and to add a vast neo-Gothic studio room with the space and light she needed. It was in the chateau that empress Eugenie presented her with her Légion d'Honneur in 1865.
The museum mainly consists of objects relating to Bonheur's everyday life (including a Native American costume given her by Buffalo Bill) and the building has remained unchanged since her death in 1899, other than the sale of all the paintings it once contained.
References:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.