The Depot de Guerre (1688 - 1887) was a branch of the French military devoted to creating, collecting, and publishing military memoirs, plans, and maps. The Depot was founded in 1688 by Francois Michel le Tellier, the Marquis de Louvois. Louvois held the post of Secretary of State for War under Louis XIV and his best known for composing the first letter regarding the mysterious "Man in the Iron Mask". During the French Revolution and the Napoleonic Wars the Depot de Guerre expanded its operations to include any and all topographical research in France. In 1887 the Depot de Guerre was disbanded and its duties split between the Institut Geographique National (IGN) and the Service Historique de L'Armee (SHA).