The bodies of the beheaded King Louis XVI, his wife Marie Antoinette of Austria, and his sister Madame Élisabeth were not initially buried in Saint-Denis, but rather in the churchyard of the Madeleine, where they were covered with quicklime.
The body of the Dauphin, who died of illness and neglect at the hands of his revolutionary captors, was buried in an unmarked grave in a Parisian churchyard near the Temple.
During Napoleon's exile in Elba, the restored Bourbons ordered a search for the corpses of Louis XVI and Marie Antoinette.
The few remains, a few bones that were presumably the king's and a clump of greyish matter containing a lady's garter, were found on 21 January 1815, brought to Saint-Denis and buried in the new Bourbon crypt.

King Louis XVIII, upon his death in 1824, was buried in the centre of the crypt, near the graves of Louis XVI and Marie Antoinette.
The coffins of royal family members who died between 1815 and 1830 were also placed in the vaults.
Under the direction of architect Viollet-le-Duc, famous for his work on Notre-Dame de Paris, church monuments that had been taken to the Museum of French Monuments were returned to the church.
The corpse of King Louis VII, who had been buried at Barbeau Abbey and whose tomb had not been touched by the revolutionaries, was brought to Saint-Denis and buried in the crypt.
In 2004, the mummified heart of the Dauphin, the boy who would have been Louis XVII, was sealed into the wall of the crypt.
The bodies of the beheaded King Louis XVI, his wife Marie Antoinette of Austria, and his sister Madame Élisabeth were not initially buried in Saint-Denis, but rather in the churchyard of the Madeleine, where they were covered with quicklime. The body of the Dauphin, who died of illness and neglect at the hands of his revolutionary captors, was buried in an unmarked grave in a Parisian churchyard near the Temple. During Napoleon's exile in Elba, the restored Bourbons ordered a search for the corpses of Louis XVI and Marie Antoinette. The few remains, a few bones that were presumably the king's and a clump of greyish matter containing a lady's garter, were found on 21 January 1815, brought to Saint-Denis and buried in the new Bourbon crypt.
King Louis XVIII, upon his death in 1824, was buried in the centre of the crypt, near the graves of Louis XVI and Marie Antoinette. The coffins of royal family members who died between 1815 and 1830 were also placed in the vaults. Under the direction of architect Viollet-le-Duc, famous for his work on Notre-Dame de Paris, church monuments that had been taken to the Museum of French Monuments were returned to the church. The corpse of King Louis VII, who had been buried at Barbeau Abbey and whose tomb had not been touched by the revolutionaries, was brought to Saint-Denis and buried in the crypt. In 2004, the mummified heart of the Dauphin, the boy who would have been Louis XVII, was sealed into the wall of the crypt.
Basilica of Saint-Denis