Battle of Charleroi

Background

By 20 August 1914 the French Fifth Army was concentrating on a 40 km front along the Sambre, centred on Charleroi and stretching east to Namur. Sordet's cavalry covered its left, and the British Expeditionary Force was concentrating at Mons.

The French plan, Plan XVII, had assumed that the Germans would come through Belgium south of the Meuse and Sambre and be concentrated in Lorraine. Joffre's armies would attack. When Lanrezac understood how large the German force in Belgium was, he wanted to shift his army to Namur to reinforce the left; Joffre refused to extend the front to about 110 km, and kept the Fifth Army near Mézières. The army then marched up to 100 km from 19 August to reach the Meuse–Sambre angle.

On 21 August Joffre told Lanrezac and the BEF that German troops were moving west, and ordered the Fifth Army to advance, with the BEF on its left to attack German forces west of the Meuse. The French planned an offensive across the Sambre, but the Germans attacked first. Between them, Bülow's Second Army pressed directly into the Meuse–Sambre angle against the Fifth Army, and Hausen's Third Army came in from the east over the Meuse. Lanrezac, in short, was caught between an order to advance and a growing threat on both flanks.

The armies

The French Fifth Army had 15 divisions after transfers to Lorraine, against 18 German divisions in the Second and Third Armies (Doughty, as reported in s2). I could not find a source with the men or guns for either side. CDB90 gives 440,000 Germans and 254,000 French; see flags.

In the French order of battle I Corps (Franchet d'Espèrey) held the Meuse from Givet to Namur, X Corps (Defforges) faced north-west along the Sambre, III Corps (Sauret) was opposite Charleroi, and XVIII Corps lay further left, with Sordet's I Cavalry Corps covering the flank. The German Second Army had the II, III, IV and IX Corps and the Guard Corps, and the Third Army the XI, XII (Saxon) and XIX (Saxon) Corps, with cavalry corps for each.

Joffre would later blame the infantry for lacking offensive spirit; Doughty, as reported in s2, called that 'pure balderdash'. On 21 August Plan XVII also had the French Third and Fourth Armies moving towards Arlon and Neufchâteau, away from the Fifth Army's fight.

The battle

21 August. Lanrezac put the Fifth Army on the Sambre. Unknown to him, German elements had already clashed with his vanguards between Namur and Charleroi. At about 4 pm he was told that the Germans were still moving west, and at 8 pm Joffre gave him discretion over when to launch his offensive. Vanguards of the 19th Division held positions between Floriffoux and Jemeppe-sur-Sambre against German assaults. At Arsimont the French were forced out and withdrew by 9 pm; the Germans had crossed the Sambre. On the III Corps front, about 3 pm, the Germans attacked the outposts of the 5th Division and forced passages at Tamines, Roselies and Aiseau. A French counter-attack retook Aiseau but failed to dislodge the Germans elsewhere. This is CDB90's THE SAMBRE.

22 August. Lanrezac reported the German attack on Namur to Joffre and asked that the Fourth Army act as soon as possible. Franchet d'Espèrey's planned moves on the French right were halted when the XII Saxon Corps attacked at the Dinant and Anseremme bridges. At 2:15 pm Lanrezac authorised the demolition of the Meuse bridges except at Givet, Hastière and Dinant. A French counter-attack in the centre failed, according to Doughty (s2).

23 August. The French centre around Charleroi began to fall back. The German Third Army crossed the Meuse and attacked the French right, held by I Corps. I Corps stopped the advance with a counter-attack but the threat to the Fifth Army's line of retreat remained. Namur was evacuated and news came of the Fourth Army's retreat from the Ardennes. About midnight Lanrezac ordered the Fifth Army to withdraw towards Givet to avoid encirclement. On the same day, to the west, the German First Army attacked the British at Mons: German IX Corps crossed the Mons–Condé Canal east of Nimy and Mons was occupied, though the British held the high ground to the east and pushed the attackers back. Kluck's staff believed only part of the BEF had been engaged and planned an envelopment for 25 August (Humphries and Maker, via s2).

24 August. Joffre ordered a general withdrawal to a line from Verdun to Mézières and Maubeuge. By the time of the Fifth Army's larger withdrawal the army had fallen back about 16 km from the Sambre, according to a source quoted in s2. The retreat that Lanrezac had begun on the night of 23 August was now part of a general withdrawal of the Allied left, which for the BEF lasted until 5 September.

Aftermath

The sources I read give no clear figures for losses. Brose records some 10,000 Fifth Army casualties, and Spears about 11,000 German Second Army casualties, with 4,000 French prisoners and 35 guns taken. The whole Battle of the Frontiers cost the French about 140,000 of the 260,000 casualties of the first month, in the last four days, according to Stevenson (s8, via s2), with about 27,000 killed on 22 August alone; Charleroi was only one part of it.

The Wikipedia article argues that the retreat 'arguably saved the French army from decisive defeat' by preventing the envelopment the Schlieffen Plan sought. The French were then pushed back to within miles of Paris after a further defensive action at St Quentin. Joffre sacked Lanrezac on 3 September, four days after he removed General Pierre Ruffey of the Third Army, and Franchet d'Espèrey replaced him. The BEF retreated from Mons until 5 September.

The battle is also remembered in literature: Pierre Drieu La Rochelle's novel The Comedy of Charleroi (1934) takes its title from it. The argument over it is mostly about blame. Joffre blamed the infantry's lack of offensive spirit; Doughty rejects that; and s1 presents Lanrezac's decision to retreat as the move that saved the army, a view I have not tested against other authors.

Wargaming it

Charleroi is a good army-level game at a brigade or regiment per counter on a front of about 40 km and three days, played in two linked sectors: the Sambre crossings at Charleroi (III Corps and X Corps against the German Second Army) and the Meuse at Dinant (I Corps against the Third Army).

The key terrain is the river: the Sambre bridges and the Meuse bridges at Givet, Hastière and Dinant, which Lanrezac left standing. The German objective is to cross, and the French to hold or counter-attack; but the real question, as in the historical battle, is when and whether the French commander decides to break off. A rule that makes the Fifth Army player choose between Joffre's offensive orders and the danger on his flanks, and that scores a French 'win' for extracting the army intact, would reproduce the dilemma. Hidden French orders and Joffre's discretion, given at 8 pm on 21 August, are good material for a command-friction mechanic.

For scenarios, the Arsimont, Tamines–Roselies–Aiseau and Dinant fights are each a good single-day game at a smaller scale. The 'what if' is Joffre's: had he let Lanrezac shift to Namur earlier, would the Fifth Army have met the German armies in better order? And would the Fourth Army's attack on 22 August, which Lanrezac asked for, have changed the Fifth Army's position?

Maps and pictures