This title of nobility seems to have been created in 832 by Emperor Louis the Pious for William, the youngest son of Adrian, Count of Orléans.

Over a few decades, the county was gathered to the royal lands of France until the end of the 9th century, before being relegated to the status of viscount.

His descendants, called House of Blois ended up related to a large number of European noble families.

On August 6, 1626, after a failed conspiracy in Nantes, Duke Gaston reluctantly accepted to marry the wealthy lady Duchess Marie of Montpensier, as Cardinal Richelieu wanted him to do.

King Louis XIV decided to give it to his own younger brother, Duke Philippe, excepted Bloisian (and so the châteaux of Blois and Chambord) as well as Languedoc.