 Aachen developed into the leading fashionable spa on the continent and maintained this position until the French occupation period at the end of the 18th century.The most important spa building of the 18th century is the "Neue Redoubt", which was built from 1782 to 1786 by the architect, Jakob Couven.As the centre of society life, the building is a direct forerunner of this type of spa house that became widespread during the 19th century.