Although intended for use by the Austro-Hungarian Army, against Italian fortifications, their first use came on the Western Front in a historically decisive campaign at the start of World War I. Germany planned to invade France by passing through the neutral country of Belgium, in order to attack France's less defended Northern flank. This involved assaulting the Belgian forts, particularly Liège and its ring of forts, which began on the 6 August 1914 with a rapid assault, repulsed by the Belgians, and which then developed into a protracted siege. This was what the forts had been designed to withstand and they were expected to hold out for at least a month, allowing time for a counterattack to be mounted.