The city wall was probably built in the 1st half of the 13th century, at the same time as the castle. The oldest fortification secured the "city quarter" from the church to the Mainz Gate Tower. The Rhine front was probably already built on the inside with residential houses since the 13th century; the building over of the fortification corridor took place only since the 17th/18th century.

The church protrudes like a bulwark from the essentially preserved wall alignment and therefore seems to be younger. A first extension, probably at the end of the 13th century, enclosed the electoral official cellar and customs clerk's office, the southern corner of which is formed by the mighty so-called customs clerk's tower, renewed in 1485. Probably with the city rights in 1324 a second extension of the walls took place to protect the gradually developed market and beech quarter with market place, Alleestraße, Blücherstraße.

The so-called Wesel Tower with three polygonal corner towers and a tower in the Blücher Valley, the so-called "Philippine Castle", have been preserved. The third extension from the time around 1485-87 protected the long Zöller quarter (Zollstraße) in the south and ended with the mighty "Dicken Turm" (Thick Tower), a characteristic round tower with a twelve-cornered, wooden rampart. In the area around the market square and Metzgergasse, numerous houses can still be reached today (practically, especially during high water) via the former battlements.

Source: Dehio; Krämer; redakt. Ed. S.G.