If the first fortifications of Briançon date back to Roman times, it is especially in the 17th century, to respond to the threat of the Dukes of Savoy, that Louis XIV undertook the modernization of the medieval urban wall of the city and the necessary developments of its military protection. In the 18th century, Briançon remained a front-line place facing Savoy and continued to be the subject of all the attentions of the French military engineers.