Including himself in the dynamics of post-medieval developments in the art of fortification, Vauban (1633-1707), wishing to reduce human losses, revolutionized the arts of poliorcetics and fortification. Three fortification systems can be deduced from the works made by Vauban. However, he seeks above all to adapt to the terrain13.
The conquest of Franche-Comté and the Holy Roman Empire by the Dutch War in 1674 made the fortification of the Belfort region, giving access to the plain of Alsace, essential. According to Vauban's pre-square double barrier system, Belfort is in the second line behind Huningue and Neuf-Brisach. Belfort, from a simple fortification still of medieval essence, then acquired the status of royal fortress.
The fortification project of Belfort proposed in 1687, following the formation of the league of Augsburg, according to its second theoretical system. This system is based on the separation of the long and close firing zones into two concentric enclosures. The outer enclosure is made up of detached fortified bastions overlooking the field. The inner enclosure is dedicated to close combat. This inner enclosure is formed from towers 27, 41 and 4614.
Vauban adapts the terrain by moving the Savoureuse river and adapts to the terrain by advancing a protective work facing the Miotte - it is the Horn of Hope -, and another on the glacis of the castle.