Fortress Koblenz-Feste Kaiser Franz

Planning for the Feste Kaiser Franz began in 1814 under General Ernst Ludwig von Aster. Between 1816 and 1822, the fortress was constructed according to designs by Claudius Franz Le Bauld de Nans and named after Emperor Franz I in 1818, an ally of Prussia. After its completion in 1822 and occupation by troops in 1823, extensive reconstruction and stabilization measures followed in 1834/35 and 1841/43 due to structural damage. During the Franco-Prussian War of 1870/71, the site served as a prisoner-of-war camp. With the acquisition of French fortresses in Alsace, the Feste Kaiser Franz lost strategic importance and was abandoned in 1890, though it initially remained under military administration.