Fortifications of Frankfurt

The fortifications of Frankfurt were a system of military defences of the German city of Frankfurt am Main which existed from the Middle Ages into the 19th century. Around 1000 the first city wall was built. It enclosed the area of what is now the Königspfalz in modern Frankfurt. In the twelfth century the settlement expanded into what is now Altstadt. For its protection an additional wall, the Staufenmauer, was erected. Starting in 1333, the Neustadt suburb developed north of the Altstadt and was encompassed by an additional wall with five gates. In the fifteenth century, a "landwehr border" was created around the entire territory of the Free City of Frankfurt. Beginning in 1628, the medieval city wall was developed to form a bastion fortress under the municipal architect Johann Dilich. After its defeat in the Kronberg Feud in 1389, Frankfurt consistently avoided military conflicts and relied on its diplomatic relationships throughout the Holy Roman Empire and beyond. For this reason, the city's fortifications, during the nearly eight centuries of their existence, have only had to stand a siege once - during the Second Schmalkaldic War, in July 1552. During the eighteenth century the fortifications lost their military significance and hindered further expansion of the city: the walls were torn down between 1806 and 1818. Their former position now forms a green belt around the inner city. Various components of the fortifications are preserved, including: seven towers, among them the Eschenheimer Turm; a 200-metre stretch of the Staufenmauer; remnants of the landwehr border; and a 90-metre section of a casemate, discovered in 2009, which once formed part of the baroque bastion fortress. Frankfurt's oldest fortifications were created to protect the Carolingian palace (German: Karolingische Pfalz) which was first recorded in 822. Until the 1930s it was thought to have been a predecessor of today's Saalhof. In 1936, Heinrich Bingemer proved by excavations that this originated in the Hohenstaufen era, and concluded that the site of the Carolingian palace may have been located further to the east.