Nave of the veteran's chapel, adorned with military flags.

Part of Les Invalides complex built for veterans, this was the first chapel built. In 1676 Hardouin Mansart was commissioned to build the church of the Hôtel des Invalides, after Libéral Bruand, who designed the rest of the complex, failed to produce a satisfactory scheme. For this almost monastic establishment for disabled soldiers, Hardouin Mansart created a bipartite building: the first part Église St-Louis, a nine-bay nave for the pensioners, has a barrel vault and side aisles with tribunes opening through flattened arches, following 17th-century French models. The vault, decorated with the military trophies of France, houses the governors crypt, where many governors of the Invalides, marshals of France and great military leaders lie. Dedicated to Saint Louis and consecrated to the Holy Trinity , the Church is administratively attached to the Musée de l'Armée since the museum's creation in 1905.