Wikipedia
Thymerais (or Thimerais) is a natural region of Eure-et-Loir, in France, where history and geography meet. Open to influences from Normandy, Drouais, Beauce and Perche, it is a transition zone like the Drouais.
A former country of Perche under the Merovingian dynasty, it took its name from its allegiance to Theodemer, prince of the Merovingian family.
Thymerais is also associated with the barony of Châteauneuf-en-Thymerais whose territory included in the thirteenth century the north-west of the Eure-et-Loir and some villages in Drouais, Eure and Orne, and overflowed the present townships of Courville-sur-Eure and La Loupe.
The name Thymerais was taken in 2003 to designate the district of Thymerais municipalities made of communes belonging to the canton of Châteauneuf-en-Thymerais. Châteauneuf-en-Thymerais and Thimert-Gâtelles are the historic centers of this district.