Over the next centuries, Tarasp was occupied by a number of administrators, but remained under Austrian control. By the 18th century Tarasp was the only Austrian territory in Switzerland. Throughout this period, the castle was often expanded and renovated to its present appearance. After the French invasion of Switzerland and the creation of the Helvetic Republic, in 1803 the castle was taken from the Austrians and given to the Republic. A few months later, when the Republic collapsed, the castle was transferred to the newly created Canton of Graubünden. After about 1815 the castle was abandoned and rapidly fell into ruin.