Paris-Bayonne telegraph line. On 5 June 1874, Alfred Cornu tried to calculate the speed of light between the tower and the Observatory in Paris. During the Franco-Prussian War, the town was occupied and pillaged by the Prussians. It was occupied again by Germany in 1940 during the Second World War. Today Montlhéry is twinned with Stetten am kalten Markt, Germany. Population Inhabitants of Montlhéry are known as Montlhériens in French. Château de Montlhéry The Château de Montlhéry, a 13th-century castle with its prominent keep, succeeded a castle built in the 11th century, and an earlier foundation, built from 991 to 1015. List of lords of Montlhéry Thibaud of Montmorency (970-1031) Guy I of Montlhéry (1031–1095) Milo I of Montlhéry (1095–1102) Guy II of Montlhéry (1102–1109) Milo II of Montlhéry (1109–1118) passes to royal domain of France Economy South of Montlhéry (on the communes of Linas and Bruyères-le-Châtel) is the site of an automobile race track, the Autodrome de Montlhéry, established by Alexandre Lamblin in 1924. It is sometimes referred to as the 'French Indianapolis', because it is laid out as a high speed oval. Many speed records were set there within months of its opening. Today the racetrack has fallen into disuse and is also used for other purposes including a variety of automobile meetups. Montlhéry was also a market town, which is remembered today in the Tomato Festival. The medieval tower is also a popular tourist attraction, which recently re-opened in 2005 after being closed for repairs. Personalities Henri Oreiller, was an alpine ski racer and Olympic gold medalist from France. Paul Fort, nicknamed Le Prince des Poètes lived there from 1921 until his death in 1960. See also Communes of the Essonne department References History and Archaeology of the Castle, on Montlhéry.com External links City council website (in French) Website about Montlhéry Mayors of Essonne Association Communes of Essonne