Poigny-la-Forêt is a commune in the Yvelines department in the Île-de-France in north-central France.
The name of the town comes from the Celtic word Pugneis meaning "clearing in the woods."
In the twelfth century, the Order of Grandmont (Haute-Vienne) founded the priory of Notre-Dame-des-Moulineaux. In 1317, following the reorganization of the Order, it became part of Ouye (see Dourdan). In 1576, the family of Angennes Poigny who ruled, built a castle. From 1643 the site has been in disrepair. Today, you can still see the choir of the church and the remains of the wall along the D107 near the rocks Angennes.
In 2008, Poigny la Forest had 1032 inhabitants (an increase of 18% compared to 1999). The town is located at the 219th position, 9 at the national level, it had been 9 at the 738th in 1999 and the 139th at the departmental level of 262 municipalities.
Changes in the number of inhabitants is known throughout the population censuses conducted in Poigny la Forest since 1793.
At the turn of the century, the methods of census were amended by Act of February 27, 2002, called the law of local democracy, so that after a transitional period of 2004-2008, the annual population varieted with different French administrative districts.
For municipalities with populations less than 10,000 inhabitants, investigations are comprehensive and take place every year in rotation over a period of five years . For Poigny-la-Forêt, the first census was taken in 2008, the following will be in 2013, 2018, etc.. The peak population was reached in 2008 with 1032 inhabitants.