The German invasion
Following the Sarajevo crime, a series of alliances between several European powers took shape: the Triple Entente (France, UK, Russia and the powers they controlled as large colonial powers) and the Triple Alliance (Germany, Austro-Hungary and the empires under their control). There was fighting along various fronts, especially in Europe, but also in part of Asia and Africa.
Considering the protocol of 1851 on the neutrality of Belgium to be a mere piece of paper, the German Chief of Staff planned to violate Belgian neutrality to enter France from the North and the Ardennes. The plains of Picardy would then open up before the German army, affording it an easy route down to Paris, to then take from the rear the French troops stationed in the East.
On 4 August 1914, the German Chief of Staff sent more than 700,000 men to launch an attack on Belgium. In accordance with the Schlieffen Plan, he gave himself six weeks to take Paris and annihilate the French army which was bogged down in Alsace-Lorraine before then returning to the East. From this point of view, Maubeuge, located at the intersection of the railways, constituted an important strategic objective.
By mobilising considerable numbers of infantry, cavalry and artillery, the German Chief of Staff intended to cross neutral Belgium to then take Paris. Despite the resistance put up by the Belgian and French armies, supported by the British Expeditionary Force around Liège, Namur and Mons, the German advance continued towards the Franco-Belgian frontier, forcing the Allies to retreat.