The origin of Thymerais goes back to the 7th century, when king Thierry III gave this territory to Theodemer, prince of the Merovingian family. The country was then called
Theodemerensis (literally "Theodemer Territory") in his honor, then abbreviated to
Themerensis and gallicized to
Thymerais or
Thimerais. The country was attached to the
Kingdom of France in the 12th and 13th centuries. According to the vicomte de Romanet, the Thymerais territory that was originally part of the counties of Chartres and Dreux, was occupied by powerful independent lords who owed allegiance only to the King of France. On the religious side, the Thymerais belonged to the diocese of Chartres, on its north-west. It was composed of 14 parishes. In 1058, Albert Ribaud, lord of Thymerais, took a stand against
William the Conqueror, Duke of Normandy and king of England, who seized Thimert and then installed there a governor. The following year,
Henry I, King of the Franks,
retook the castle and razed it. Not very far, in a clearing in the woods, Gaston, brother of Albert Ribaud, built a fort named
Chastel-neuf, which soon was surrounded by a village of the same name, and which became the capital of Thymerais. From a feudal standpoint, the Thymerais formed in 1200 one great fief with
Châteauneuf-en-Thymerais at its center. This fief was divided into two parts, both dependencies of the Crown of France. On one side Châteauneuf, and on the other Senonches and Brezolles, erected later into Senonches county. In the 18th century,
La Ferté-Vidame was distracted from the barony of Châteauneuf-en-Thymerais and attached to the Crown of France, as were those of Maillebois and Blévy; thus, until the late 18th century, the barony of Châteauneuf-en-Thymerais was far from having the same extent it had in the 13th century. Also, instead of being a single fief, the Thymerais was composed of four: the barony of Châteauneuf, the county of Senonches, the marquisat of Maillebois and the county of La Ferté-Vidame. In financial and administrative terms, the Thimerais was part of Verneuil-sur-Avre, included in the
Généralité of
Alençon, and divided into four subdivisions (Thimerais addition, still included eight parishes in the province of Perche since the abolition of the election
Longny-au-Perche in 1080 and a number of the Norman parishes). In military terms, the Thimerais was part of the government of the
Île de France and there was in Châteauneuf a
constabulary and archers. ==References==