From the English Wikipedia page 
In France, the Defence Historical Service (Service historique de la défense or SHD) is the archives centre of Ministry of Defence and its armed forces. It was set up by decree in 2005.
The SHD consists of the "Centre historique des archives" at Vincennes, the "Centre des archives de l’armement et du personnel" at Châtellerault and a number of smaller repositories. In total the archives contain about 300 km of records of which 100 km are at Vincennes and 70 km at Châtellerault.
More information on the French Wikipedia page 
The website is