German invasion of Belgium

The German invasion of Belgium was a military campaign which began on 4 August 1914. Earlier, on 24 July, the Belgian government had announced that if war came it would uphold its historic neutrality. The Belgian government mobilised its armed forces on 31 July and a state of heightened alert (Kriegsgefahr) was proclaimed in Germany. On 2 August, the German government sent an ultimatum to Belgium, demanding passage through the country and German forces invaded Luxembourg. Two days later, the Belgian Government refused the demands and the British Government guaranteed military support to Belgium. The German government declared war on Belgium on 4 August, troops crossed the border and began the Battle of Liège.

German military operations in Belgium were intended to bring the 1st, 2nd and 3rd armies into positions in Belgium from which they could invade France, which after the fall of Liège on 7 August, led to sieges of Belgian fortresses along the Meuse river at Namur and the surrender of the last forts (16–17 August). The government abandoned the capital, Brussels, on 17 August and after fighting on the Gete river, the Belgian field army withdrew westwards to the National Redoubt at Antwerp on 19 August. Brussels was occupied the following day and the Siege of Namur began on 21 August.

After the Battle of Mons and the Battle of Charleroi, the bulk of the German armies marched south into France, leaving small forces to garrison Brussels and the Belgian railways. The III Reserve Corps advanced to the fortified zone around Antwerp and a division of the IV Reserve Corps took over in Brussels. The Belgian field army made several sorties from Antwerp in late August and September to harass German communications and to assist the French and the British Expeditionary Force (BEF), by keeping German troops in Belgium. German troop withdrawals to reinforce the main armies in France were postponed to repulse a Belgian sortie from 9 to 13 September and a German corps in transit was retained in Belgium for several days. Belgian resistance and German fear of francs-tireurs, led the Germans to implement a policy of terror (schrecklichkeit) against Belgian civilians soon after the invasion, in which massacres, executions, hostage taking and the burning of towns and villages took place and became known as the Rape of Belgium.

While the French armies and the BEF began the Great Retreat into France (24 August – 28 September), the Belgian army and small detachments of French and British troops fought in Belgium against German cavalry and Jäger. On 27 August, a squadron of the Royal Naval Air Service (RNAS) flew to Ostend, to conduct air reconnaissance between Bruges, Ghent and Ypres. British marines landed in France on 19/20 September and began scouting unoccupied Belgium in motor cars; an RNAS Armoured Car Section was created by fitting vehicles with bulletproof steel. On 2 October, the Marine Brigade of the Royal Naval Division was moved to Antwerp, followed by the rest of the division on 6 October. From 6 to 7 October, the 7th Division and the 3rd Cavalry Division landed at Zeebrugge and naval forces collected at Dover were formed into the Dover Patrol, to operate in the Channel and off the French–Belgian coast. Despite minor British reinforcement, the Siege of Antwerp ended when its defensive ring of forts was destroyed by German super-heavy artillery. The city was abandoned on 9 October and Allied forces withdrew to West Flanders.

At the end of the Great Retreat, the Race to the Sea (17 September – 19 October) began, a period of reciprocal attempts by the Germans and Franco-British to outflank their opponents, extending the front line northwards from the Aisne, into Picardy, Artois and Flanders. Military operations in Belgium also moved westwards as the Belgian army withdrew from Antwerp to the area close to the border with France. The Belgian army fought a the defensive Battle of the Yser (16–31 October) from Nieuport south to Dixmude, as the German 4th Army attacked westwards and French, British and some Belgian troops fought the First Battle of Ypres (19 October – 22 November) against the 4th and 6th armies. By November 1914, most of Belgium was under German occupation and Allied naval blockade. A German military administration was established on 26 August 1914, to rule through the pre-war Belgian administrative system, overseen by a small group of German officers and officials. Belgium was divided into administrative zones, the General Government of Brussels and its hinterland; a second zone, under the 4th Army, including Ghent and Antwerp and a third zone under the German Navy along the coastline. The German occupation lasted until late 1918.


Belgian neutrality

Map of Europe in 1914

The 1839 Treaty of London recognised Belgium as an independent and neutral state.[1] Until 1911, Belgian strategic analysis anticipated that if war came, the Germans would attack France across the Franco-German border and trap the French armies against the Belgian frontier, as they had done in 1870. British and French guarantees of Belgian independence were made before 1914 but the possibility of landings in Antwerp was floated by the British military attaché in 1906 and 1911, which led the Belgians to suspect that the British had come to see Belgian neutrality as a matter of British diplomatic and military advantage, rather than as an end in itself. The Agadir Crisis (1911) left the Belgian government in little doubt as to the risk of a European war and an invasion of Belgium by Germany.[2]

In September 1911, a government meeting concluded that Belgium must be prepared to resist a German invasion, to avoid accusations of collusion by the British and French governments. Britain, France and the Netherlands were also to continue to be treated as potential enemies.[2] In 1913 and 1914, the Germans made inquires to the Belgian military attaché in Berlin, about the passage of German military forces through Belgium. If invaded, Belgium would need foreign help but would not treat foreign powers as allies or form objectives beyond the maintenance of Belgian independence. Neutrality forced the Belgian government into a strategy of military independence, based on a rearmament programme begun in 1909, which was expected to be complete in 1926. The Belgian plan was to have three army corps, to reduce the numerical advantage of the German armies over the French, intended to deter a German invasion.[3]

Conscription began in 1909 but with a reduction in the term of service to fifteen months; the Agadir Crisis made the government continue its preparations but until 1913, the size of the army was not fixed as a proportion of the population. The annual conscription of 13,300 recruits was increased to 33,000 to accumulate the trained manpower for a field army of 180,000 men. Older men would continue to serve as garrison troops and by 1926 340,000 men would be available. Implementation of the new scheme had disrupted the old one but had not become effective by 1914. During the crisis over the assassination of Archduke Franz Ferdinand of Austria, regiments were divided and eight conscription classes were incorporated into the army to provide 117,000 men for the field army and 200,000 fortress troops. The Belgian army planned all-round defence, rather than concentrating the army against a particular threat. Belgian defences were to be based on a National Redoubt at Antwerp, with the field army massed in the centre of the country 60 kilometres (37 mi) from the border, ready to manoeuvre to delay an invasion, while the frontiers were protected by the fortified regions of Liège and Namur.[3] The German invasion of Belgium on 4 August 1914, in violation of Article VII of the Treaty of London was the Causus belli, the reason given by the British government, for declaring war on Germany.[4]

War plans

Belgian defensive plans

Headline in Le Soir, 4 August 1914

Belgian military planning was based on the 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 to do more than protect its independence. The Anglo-French Entente (1904) had led the Belgians to perceive that the British attitude to Belgium had changed and that it was now 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 not replaced until May 1914 by Lieutenant-General Chevalier de Selliers de Moranville. Moranville began planning for the concentration of the army and met railway officials on 29 July.[5]

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 conscripts would benefit from a central position to delay contact with an invader. The army would also need fortifications for defence but these had been built on the frontier. Another school of thought wanted a return to a frontier deployment, in line with French theories of the offensive. The Belgian plan that emerged was a compromise in which the field army concentrated behind the Gete river with two divisions forward at Liège and Namur.[5]

Germany: Schlieffen–Moltke Plan

German strategy had given priority to offensive operations against France and a defensive posture against Russia since 1891. German planning was determined by numerical inferiority, the speed of mobilisation and concentration and the effect of the vast increase of the power of modern weapons. Frontal attacks were expected to be costly and protracted, leading to limited success, particularly after the French and Russians modernised their fortifications on the frontiers with Germany. Alfred von Schlieffen, Chief of the Imperial German General Staff (Oberste Heeresleitung, OHL) from 1891 to 1906 devised a plan to evade the French frontier fortifications, with an offensive on the northern flank, which would have a local numerical superiority and obtain rapidly a decisive victory. By 1898–1899, such a manoeuvre was intended to swiftly pass between Antwerp and Namur and threaten Paris from the north.[6]

Eastern Front to 26 September 1914

Helmuth von Moltke the Younger succeeded Schlieffen in 1906 and was less certain that the French would conform to German assumptions. Moltke adapted the deployment and concentration plan to accommodate an attack in the centre or an enveloping attack from both flanks as variants, by adding divisions to the left flank opposite the French frontier, from the c. 1,700,000 men expected to be mobilised in the Westheer (Western Army). The main German force would still advance through Belgium and attack southwards into France, the French armies would be enveloped on the left and pressed back over the Meuse, Aisne, Somme, Oise, Marne and Seine, by short, rapid attacks, unable to withdraw into central France. The French would either be annihilated or the manoeuvre from the north would create conditions for victory in the centre or in Lorraine, on the common border.[7]

A corollary to the emphasis on the Western Front was a lack of troops for the Eastern Front against Russia. In the east the Germans planned a defensive strategy and relied on the Austro-Hungarian Army (Landstreitkräfte Österreich-Ungarns/Császári és Királyi Hadsereg) to divert the Russians from East Prussia, while France was crushed. Divisions from the German army in the west (Westheer) would be redeployed to the East to deal with the Russians as soon as a breathing-space was gained against the French.[8]

France: Plan XVII

Depiction of Albert I, King of the Belgians; Albert became king in 1909 and commanded the Belgian army throughout World War I

Under Plan XVII the French peacetime army was to form five field armies, with a group of reserve divisions attached to each army and a group of reserve divisions on each flank, a military force of c. 2,000,000 men. The armies were to concentrate opposite the German frontier around Épinal, Nancy and Verdun–Mezières, with an army in reserve around Ste. Ménéhould and Commercy. Since 1871, railway building had given the French General Staff sixteen lines to the German frontier, against thirteen available to the German army and the French could afford to wait until German intentions were clear. The French deployment was intended to be ready for a German offensive in Lorraine or through Belgium. It was anticipated that the Germans would use reserve troops but also expected that a large German army would be mobilised on the border with Russia, leaving the western army with sufficient troops only to advance through Belgium south of the Meuse and the Sambre rivers. French intelligence had obtained a 1905 map exercise of the German general staff, in which German troops had gone no further north than Namur and assumed that plans to besiege Belgian forts were a defensive measure against the Belgian army.[9]

A German attack from south-eastern Belgium towards Mézières and a possible offensive from Lorraine towards Verdun, Nancy and St. Dié was anticipated; the plan was an evolution from Plan XVI and made more provision for the possibility of a German offensive from the north through Belgium. The First, Second and Third armies were to concentrate between Épinal and Verdun opposite Alsace and Lorraine, the Fifth Army was to assemble from Montmédy to Sedan and Mézières and the Fourth Army was to be held back west of Verdun, ready to move east to attack the southern flank of a German invasion through Belgium or southwards against the northern flank of an attack through Lorraine. No formal provision was made for combined operations with the British Expeditionary Force (BEF) but joint arrangements had been made and in 1911 during the Second Moroccan Crisis, the French had been told that six British divisions could be expected to operate around Maubeuge.[10]