The Château de Chaumont is a French castle. It was the first château at Chaumont-sur-Loire, Loir-et-Cher, France. It was built by Eudes II, Count of Blois, in the 10th century with the purpose of serving as a fortress to protect the Blois from attacks.
The castle was burned to the ground in 1465 in accordance with Louis XI's orders and was later rebuilt by Charles I d'Amboise from 1465-1475 and then finished by his son, Charles II d'Amboise de Chaumont from 1498-1510, with help from his uncle, Georges d'Amboise.
Château Chaumont was later purchased by Catherine de Medici in 1560, a year after her late husband Henry II's death. She entertained numerous astrologers there, among them Nostradamus. After a short while, she forced Diane de Poitiers, Henry II's long-term mistress, to exchange Château de Chenonceau for Château de Chaumont. Diane de Poitiers only lived there for a short while.