With the establishment of Belgian rule several defensive problems surfaced. The Wellington barrier in the south of Belgium could not be maintained since it would cause a serious stress on the young country’s defensive capabilities. Moreover Belgium had to abide to strict neutrality. This implied that the country should fend off any attacking force: Belgium could not conduct offensive operations and all borders should be treated as an equal risk. In wake of the French political upheavals of 1848 it was feared that France would once again invade Belgium.
Belgian defense concept 1839-1851
It was decided that the barrier defenses would be dismantled. Only a selection of fortresses were to be maintained and expanded if needed. Namur would secure the southern access to France while Liège keeps Prussia at bay. The citadel of Diest and the cities of Dendermonde (Termonde) and Gent (Ghent) are considered to be strong points as well. Antwerp was chosen to be the national fortress (reduit national) because of its natural defenses and access to the river Scheldt. In times of peril the so called signatories (garanten) of the Belgian neutrality should have easy access to the country in order to stop any attacking nation. The British Empire would need a viable port to disembark its army so Antwerp seemed the premier location.
To protect the city from enemy bombardment a series of smaller redoubts were constructed. The older Spanish fortifications were deemed outdated because of advances in artillery technology. Later these redoubts were upgraded with brick main buildings and the side facing the city was being equipped with a rampart. These additions made them the first Belgian forts around Antwerp but public opinion did not approve since the events and memories of 1832 were still fresh. The Belgian military concluded that these forts did not offer sufficient defensive capabilities. Therefore a new defensive concept was needed. A young Belgian military engineer named Brialmont would come up with an ambitious solution.