The Battle of Liège (5–16 August 1914) was the opening engagement of the German invasion of Belgium and the first battle of the First World War. The city of Liège was protected by a ring of modern fortresses, one of several fortified cities intended to delay an invasion for troops from the powers guaranteeing Belgian neutrality to mobilise and join the Belgian Army in the expulsion of the invader.
The German 1st Army arrived late 5 August 1914 and captured the city on 7 August when Erich Ludendorff drove in and convinced the garrison to surrender. The surrounding forts fought on and several attacks by German infantry were costly failures. Super-heavy siege guns arrived and destroyed the forts one by one; the last fort surrendered on 16 August.
The siege of Liège may have delayed the German invasion of France by four to five days. Railways in the Meuse river valley needed by the German armies in eastern Belgium were closed for the duration of the siege and German troops did not appear in strength before the city of Namur at the confluence of the Sambre and Meuse rivers until 20 August. With the experience gained at Liège, the German 2nd Army completed the Siege of Namur in two days.
Background
Strategic developments
Belgium
Belgian military planning was based on an assumption that other powers would expel an invader. The likelihood of a German invasion did not lead to France and Britain being seen as allies or for the Belgian government to intend 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 seen as a British protectorate. A General Staff was formed in 1910 but the Chef d'État-Major Général de l'Armée (Chief of the General Staff), Lieutenant-Général Harry Jungbluth was retired on 30 June 1912 and not replaced until May 1914 by Lieutenant-General Chevalier de Selliers de Moranville who began planning 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 ready to face any border. 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 Gete River with two divisions forward at Liège and Namur.
Germany
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 1891–1906, 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 pass swiftly through Belgium, between Antwerp and Namur and threaten Paris from the north. 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 which were expected to be mobilised in the Westheer (western army). The main German force would still advance through Belgium to attack southwards into France, the French armies would be enveloped on their left and pressed back over the Meuse, Aisne, Somme, Oise, Marne and Seine rivers, unable to withdraw into central France. The French would either be annihilated by the manoeuvre from the north or it would create conditions for victory in the centre or in Lorraine on the common border.
Declarations of war
At midnight on 31 July/1 August, the German government sent an ultimatum to Russia and announced a state of Kriegsgefahr during the day; the Ottoman government ordered mobilisation and the London Stock Exchange closed. On 1 August the British government ordered the mobilisation of the navy, the German government ordered general mobilisation and declared war on Russia. Hostilities commenced on the Polish frontier, the French government ordered general mobilisation and next day the German government sent an ultimatum to Belgium, demanding passage through Belgian territory, as German troops crossed the frontier of Luxembourg. Military operations began on the French frontier, Libau was bombarded by a German light cruiser SMS Augsburg and the British government guaranteed naval protection for French coasts. On 3 August the Belgian Government refused German demands and the British Government guaranteed military support to Belgium, should Germany invade. Germany declared war on France, the British government ordered general mobilisation and Italy declared neutrality. On 4 August the British government sent an ultimatum to Germany and declared war on Germany at midnight on 4/5 August, Central European Time. Belgium severed diplomatic relations with Germany and Germany declared war on Belgium. German troops crossed the Belgian frontier and attacked Liège.
Tactical developments
Liège forts
Liège is situated at the confluence of the Meuse which, at the city, flows through a deep ravine and the Ourthe River, between the Ardennes to the south and Maastricht (in the Netherlands) and Flanders to the north and west. The city lies on the main rail lines from Germany to Brussels and Paris, which Schlieffen and Moltke planned to use in an invasion of France. Much industrial development had taken place in Liège and the vicinity, which presented a considerable obstacle to an invading force. The main defences were a ring of twelve forts 6–10 km (3.7–6.2 mi) from the city, built in 1892 by Henri Alexis Brialmont, the leading fortress engineer of the nineteenth century. The forts were sited about 4 km (2.5 mi) apart to be mutually supporting but had been designed for frontal, rather than all-round defence.
The forts were five large triangular (Barchon, Fléron, Boncelles, Loncin and Pontisse), four small triangular (Evegnée, Hollogne, Lantin and Liers) and two small square forts (Chaudfontaine and Embourg). The forts were built of concrete, with a surrounding ditch and barbed-wire entanglements; the superstructures were buried and only mounds of concrete or masonry and soil were visible. The large forts had two armoured turrets with two 210 mm (8.3 in) guns each, one turret with two 150 mm (5.9 in) guns and two cupolas with a 210 mm (8.3 in) howitzer each. Four retractable turrets contained a 57 mm (2.2 in) quick-firer each, two before the citadel and two at the base. A retractable searchlight was built behind the 150 mm turret with a range of 2–3 km (1.2–1.9 mi). Small forts had a 210 mm (8.3 in) howitzer cupola and three of the quick-firers. The heavy guns and quick-firers used black powder ammunition, long superseded in other armies, which raised clouds of smoke and obscured the view of the gunners. The 150 mm (5.9 in) guns had the greatest range at 8,500 m (9,300 yd) but the black powder smoke limited the realistic range to about 1,500 m (1,600 yd). The forts contained magazines for the storage of ammunition, crew quarters for up to 500 men and electric generators for lighting. Provision had been made for the daily needs of the fortress troops but the latrines, showers, kitchens and the morgue had been built in the counterscarp, which could become untenable if fumes from exploding shells accumulated, because the forts were ventilated naturally.
The forts could communicate with the outside by telephone and telegraph but the wires were not buried. Smaller fortifications and trench lines in the gaps between the forts had been planned by Brialmont but had not been built. The fortress troops were not at full strength and many men were drawn from local guard units, who had received minimal training due to the reorganisation of the Belgian army begun in 1911, which was not scheduled to be complete until 1926. The forts also had c. 26,000 soldiers and 72 field guns of the 3rd Infantry Division and 15th Infantry Brigade to defend the gaps between forts, c. 6,000 fortress troops and members of the paramilitary Garde Civique, equipped with rifles and machine-guns. The garrison of c. 32,000 men and 280 guns was insufficient to man the forts and field fortifications. In early August 1914, the garrison commander was unsure of the troops which he would have at his disposal, since until 6 August, it was possible that all of the Belgian army would advance towards the Meuse.
The terrain in the fortress zone was difficult to observe from the forts because many ravines ran between them. Interval defences had been built just before the battle but were insufficient to stop German infiltration. The forts were also vulnerable to attack from the rear, the direction from which the German bombardments were fired. The forts had been designed to withstand shelling from 210 mm (8.3 in) guns which, in 1890, were the largest mobile artillery in the world but the concrete used was not of the best quality and by 1914 the German army had the first of the much larger 420 mm howitzers, (L/12 420 mm (17 in) M-Gerät 14 Kurze Marine-Kanone) and could call on Austro-Hungarian 305 mm howitzers (Mörser M. 11). The Belgian 3rd Division (Lieutenant-General Gérard Léman) along with the attached 15th Infantry Brigade defended Liège. The division comprised five brigades and various other formations with c. 32,000 troops and 280 guns.
Army of the Meuse
The Army of the Meuse (General Otto von Emmich) consisted of the 11th Brigade of III Corps (Major-General Friedrich von Wachter), the 14th Brigade of IV Corps (Major-General Friedrich von Wussow), the 27th Brigade of VII Corps (Colonel Benno von Massow), the 34th Brigade of IX Corps (Major-General Richard von Kraewel), the 38th Brigade of X Corps (Colonel Oertzen) and the 43rd Brigade of XI Corps (Major-General Hülsen). The cavalry component consisted of Höheres Kavallerie-Kommando II (II Cavalry Corps [HKK II]), Lieutenant-General Georg von der Marwitz), consisting of the 2nd (Major-General Friedrich von Krane), 4th (Lieutenant-General Otto von Garnier) and the 9th (Major-General Karl-Ulrich von Bülow) cavalry divisions. (A German Cavalry Corps was not an army corps in the conventional sense but the largest German cavalry unit that operated in 1914 and was known as a Höheres Kavallerie-Kommando.) The Army of the Meuse had c. 59,800 troops with 100 guns and howitzers, accompanied by Erich Ludendorff as an observer for the General Staff.
Prelude
German preparations
In August 1914, the Germans realised that the garrison at Liège would be larger than anticipated and that prompt mobilisation had given the Belgians time to make progress on the defences between the forts. Six reinforced brigades and II Cavalry Corps under the X Corps commander were to be ready on 4 August, the third day of mobilisation, at Aachen, Eupen, and Malmedy to conduct the coup de main. The 2nd Army Quartermaster General, Major-General Erich Ludendorff, was assigned to the X Corps staff as he was familiar with the plan, having been the Chief of the Deployment Department of the General Staff. On the night of 5/6 August the force was to make a surprise attack, penetrate the fortress ring, capture the town and the road and rail facilities. The invasion began on 4 August; aeroplanes, cavalry and cyclists went ahead of the infantry, with leaflets requesting calm from Belgian civilians. On the right flank, II Cavalry Corps with the cavalry Division Garnier and the 34th Infantry Brigade, advanced to take the crossings over the Meuse at Visé, to reconnoitre towards Brussels and Antwerp and prevent the Belgian army from interfering with the attack on Liège.