The Battle of the Ardennes was a battle of the First World War fought on the frontiers of France, Germany, Belgium and Luxembourg from 21 to 23 August 1914. The German armies defeated the French armies and forced the French armies to retreat. The battle was part of the larger Battle of the Frontiers, the first battle of the Western Front.
Belgian military planning was based on an assumption that other powers would eject an invader but the likelihood of a German invasion did not lead to France and Britain being seen as allies or for the Belgian government intending to do more than protect its independence. The Anglo-French Entente (1904) had led the Belgian government to think that the British attitude to Belgium and that it had come to be seen as a protectorate. A Belgian General Staff was formed in 1910 but the Chef d’État-Major Général de l’Armée, Lieutenant-Général Harry Jungbluth was retired on 30 June 1912 and only replaced in May 1914 by Lieutenant-General Chevalier Antonin de Selliers de Moranville, who began work on a contingency plan for the concentration of the army and met railway officials on 29 July.
Belgian troops were to be massed in central Belgium, in front of the National redoubt of Belgium ready to face any border, while the Fortified Position of Liège and Fortified Position of Namur were left to secure the frontiers. On mobilisation, the King became Commander-in-Chief and chose where the army was to concentrate. Amid the disruption of the new rearmament plan the disorganised and poorly trained Belgian soldiers would benefit from a central position to delay contact with an invader but it would also need fortifications for defence, which were on the frontier. A school of thought wanted a return to a frontier deployment in line with French theories of the offensive. Belgian plans became a compromise in which the field army concentrated behind the river Gete with two divisions forward at Liège and Namur.