The Battle of Cambrai was fought between the British and German forces on the Western Front of World War I. It consisted of a British attack, followed by an immediate German counterattack, the largest one on the Western Front since 1914. Cambrai, an important supply point for the German Hindenburg Line, was attacked with a combination of artillery and tanks which were meant to raid the enemy positions. After an initial success on the first day, the weaknesses of the tanks made progress slow to a crawl. The rapid mobilization and efficient counter-stroke gave the Germans hope that they could achieve victory before American mobilization could overwhelm them.
The underlying impetus for what became the Battle of Cambrai was provided by an artillery specialist called Brigadier General Hugh Tudor. He conceived a plan to capitalise on the vast improvements in artillery tactics and techniques, combined with the potential to use tanks, to reintroduce surprise attacks to the Western Front battlefields. The ultimate scheme was ambitious, embracing the capture of both the German First and Second Line Systems, the crossing of the St Quentin Canal, all followed by a cavalry advance to take the railway junction at Cambrai and the tactically significant Bourlon Ridge which glowered down on the whole sector.
The problem with Cambrai was that the front was too narrow, and it was too constricted. There were canals on both sides of the front, so the attack, if successful, would be hemmed in. Moreover, for the attack to be successful in breaking through to Cambrai, a good twelve kilometers behind the lines, there had to be a massive follow-up, a task which General Émile Fayolle, with justification, had termed ‘moving an army through an army’. This was not simple.
There were three successive German lines, and it was intended to break through them all in a single bound on the first day. Because the Cambrai front had long been quiet, it was garrisoned by only two divisions, the 20th Landwehr and the 54th Reserve, supported by no more than 150 artillery guns. German troops in defensive positions had developed a series of nasty ways in which to disable tanks.
Although the guns amassed for the barrage would be the key to success, another early focus of attention was inevitably the mass use of tanks. A workable system had to be hammered out to get the tanks across No Man’s Land and the gaping trenches of the Hindenburg Line. One crucial advance was the reinvention of the fascine for the mechanical age – a huge roll of tightly bundled brushwood carried on the roof of the tank which could be dropped ahead of it to provide safe passage over a German trench.
When the British opened up their barrage at 06.20 on 20 November, it crashed down on the German lines and artillery batteries, while the creeping barrages preceded the advance of the infantry and the rumbling tanks. The Germans fell back, hoping their wide trenches would thwart the tanks: that would not be the case. Now the Germans were also harassed from the air. The men of the Royal Flying Corps, who had become increasingly involved in ground-strafing operations, were flying ahead of the tanks.
In the end the Front Line System of the Hindenburg Line was overrun to a depth of some 3-4 miles, a good achievement equal to the first day at Arras. On the other hand, the cavalry were unable to deploy forward to any effect: the German Second Line System between Masnières and Beaurevoir remained intact, the key bridge across the canal had been destroyed and the heights of Bourlon Ridge remained in German hands.
On the following day, the offensive carried on, but by now both sides found themselves in a more familiar scenario played out countless times before. The Germans rushed forward reinforcements, while the British struggled to regain some momentum. Vicious fighting took place in an effort to gain the Bourlon Ridge, but all the British had succeeded in doing was creating a vulnerable salient by the time operations staggered to a close.
When Lloyd George spoke of the false and misleading reports made to the War Cabinet by his officers, in one sense he was being unfair: the British High Command apparently believed that their boundless optimism represented the true state of affairs with respect to the Germans. The whole idea of Cambrai was based on the assumption that the Germans had been beaten so badly, were so weakened, that they could do little more than hold on by their fingernails. Instead, four days after the attack stalled, the Germans launched a major counterattack.
The German High Command was well aware of the opportunities presented by the newly created British salient. Some nine miles wide and four miles deep, it was vulnerable to attacks from both flanks to pinch it out, thereby cutting off the units holding the extremities. Soon preparations were underway for a major counterattack by the Second Army led by General Georg von der Marwitz. The end result was a plan to fire a diversionary barrage at Bourlon Wood, before attacking the southern front of the salient, driving in towards the north. The German response typified the endurance of the German Empire. Despite all the trials of the year, they still managed to scrape together a formidable force of eighteen divisions, of which ten were still largely unaffected by the recent debilitating battles on the Western Front.
The German barrage began, quietly at first but soon building up to a terrifying crescendo. As the infantry advanced, they smashed through British defences. In places they even broke through to the gun line. The Third Army awoke to near disaster: all available units were rushed forward to hold key tactical positions. The fighting degenerated into a welter of attacks and counterattacks. Eventually the British pulled back in relatively good order from the extremities of the salient, to a strong defensive line based on Flesquières – and there they stayed.
Neither side gained the objectives they craved; both did enough to deny their enemies success. The two tactical roller-coasters were rattling along side by side but for all their advances no one had yet solved the problem of breaking through their opponent’s lines. The battle ended with the honors shared, but both sides had trialled the tactics that would come to center stage in 1918.
Victory had proved as elusive as ever for the Entente in 1917. Nivelle's failure, the French Army mutinies, the misery of the Passchendaele mud and the late setback after the brilliant initial success at Cambrai all combined to cast a dark cloud over Entente hopes for the immediate future. The British Prime Minister, David Lloyd George, while still unwilling to provoke a political crisis by removing Generals William Robertson and Haig, continued to seek ways of limiting their authority and influence. So far, the assembly of United States troops had proceeded at a frustratingly slow pace. On a more constructive note, the establishment of a Supreme War Council at Versailles in November 1917 promised improved coordination of Entente strategy in the coming year.
The German Army had some reasons for optimism, at least in the short term, at the end of 1917. The new artillery and stormtroop assault tactics tested in operations at Cambrai had proved highly effective. The German formations on the Western Front were therefore retrained during the winter and were simultaneously augmented by divisions released from the Eastern Front following the Bolshevik Revolution in Russia. As 1917 ended, the Entente knew that they must expect a major German offensive in the west early the following year.