The Free Imperial City of Aachen, also known in English by its French name of Aix-la-Chapelle and today known simply as Aachen, was a Free Imperial City and spa of the Holy Roman Empire west of Cologne[1] and southeast of the Low Countries, in the Lower Rhenish–Westphalian Circle.
[1] It was too close to the frontier with the Kingdom of France to be safe, and too far from the Holy Roman Empire to be convenient as a capital city.
In 1580 Protestantism got the upper hand; an Imperial ban resulted and was imposed in 1598 by Ernest of Bavaria, archbishop-elector of Cologne.
The treaty forced the King to restore the County of Burgundy, which he had conquered, and to be content with owning twelve Flemish fortifications.
By the terms of the Treaty of Campo Formio, Aachen was incorporated in the French First Republic as chief town in the Roer Department.