The county existed until its definitive attachment to the Kingdom's lands in 1660, when Gaston, Duke of Orléans and last count of Blois, died.

From the 1st to the 5th centuries, Bloisian depended on the Carnutes oppidum of Autrium[1] (corresponding to current city of Chartres), in the Roman province of Gallia Lugdunensis Senonia.

The cheftain would have established an independent State, the Kingdom of Blois,[6] within the Roman Empire itself, when Emperor Flavius Honorius was already weakened because of repetitive raids conducted by Barbarians.

[7] The Franks established there a first county named Comitatui blesensi,[8] whose capital city was already in Blois, on the right bank of the Loire river.

They were by the way close to the Capetians since King Charlemagne married by 771 Hildegard, the Adrian's sister and daughter of Count Gerold of Anglachgau.

[14] Because he did not have any child, the county would have been transmitted to his supposed nephew, Robert the Strong,[15] who would later become Count of Orléans, Anjou, Auxerre and Nevers, but also Margrave of Neustria after 861.

By 1019, his grandson Odo II continued the Trickster's conquests by adding to the family domain the county of Meaux as well as that of Troyes in 1023.

When Count Guy II gave up his domain to Duke Louis I of Orléans, for lack of direct male descendants and in the middle of the Hundred Years' War, the county was limited to the area between the manors of Vendôme, Beaugency and Valençay.

By 1516, newly King François I ordered the conception of an ideal city, a "new Rome" -today known as Romorantin-, but it was aborted after the Leonardo da Vinci's death in 1519.

[26] Then began the construction of a huge annex castle dedicated to hunting in the forest of Chambord, in place of the old fortress built under the counts in the 10th century.

In 1626, Duke Gaston of Anjou, third son of King Henry IV, married -not without regret- the rich duchess of Montpensier, Marie de Bourbon, imposed on him by Richelieu.

After the Fronde, Duke Gaston d'Orléans, as he was called from then on, was assigned to that of Blois from 1652 and died in 1660 in his newly built residence in Blois-Vienne.

In accordance with the appanagist tradition, his titles were transferred to Duke Philippe, King Louis XIV's younger brother, but His Majesty decided not to grant him Blois as a county.

Right after the French Revolution, the department of Loir-et-Cher was created in 1790, more or less following the last borders of the county, including the cantons of Vendôme and Romorantin.