As a result of the fall of the Roman Empire, the Castellum here also fell into disrepair. Maastricht, however, remained inhabited. The first walling of the city came about because the Duke of Brabant granted the city the right to build a wall for protection at the beginning of the 13th century.

It was decided to wall up the existing buildings. A 2500 meter long wall of coal sandstone 6 to 8 meters high was built around the city, with a semicircular tower every 50 meters. Crenellations were added to the wall and on the city side there was a parapet on which the defenders could stand. This wall can be recognized by its brown color. The city area was 36 hectares. In the first rampart there were a number of gates such as Helpoort, Oude Pieterspoort , the Looierspoort, the Lenculenpoort, the Tweebergerpoort, the Grote Poort, the Leugenpoort and the Veerlinxpoort. This rampart also had small passages to reach the quays( see photo).
However, the city's expansionism was not sufficiently taken into account during construction. Thus, it was necessary to build a second wall within a century.
