Battle of Cambrai 20 November–7 December 1917: Complete Field Guide — Tanks, Surprise & Counter-Attack // Log 025

Cambrai, 20 November–7 December 1917, was not simply “the first big tank battle”. It was a deliberate attempt to solve several Western Front problems at once: cross deep wire and trenches without days of warning bombardment, suppress German guns with predicted fire, move infantry through the breach, use aircraft to support and report the advance, then release cavalry and reserves before the defence could recover.

I spent twelve years as a Royal Welsh mortarman. What catches my eye at Cambrai is not the novelty of the tank on its own; it is the relationship between fire support and movement. A fire plan can create a window. Armour can force a crossing. But unless infantry, ammunition, communications, engineers and reserves arrive in the right sequence, the window closes. Cambrai shows that in unusually clear form.

Why Cambrai — and why November 1917?

By late 1917 the British Army had spent months fighting in Flanders. Third Ypres had consumed men, ammunition and attention while demonstrating again how difficult it was to exploit local success across destroyed ground.

South-west of Cambrai the situation was different. The German Hindenburg Line — the Siegfriedstellung — was formidable, but much of the ground was firmer and less cratered. Cambrai itself was an important road and rail centre supporting the German front. A rupture here offered the possibility of threatening the defensive system from ground better suited to tanks and cavalry.

The ground and the axes of advance

The battlefield was not flat empty tank country. Several features governed the battle:

• Havrincourt and Havrincourt Wood: assembly and approach ground on the British left-centre.
• Flesquières Ridge: commanding ground and a serious obstacle to the IV Corps advance.
• Marcoing and Masnières: gateways toward the Canal de Saint-Quentin and routes deeper toward Cambrai.
• Bourlon Ridge and Bourlon Wood: high ground north-west of Cambrai. Once the initial assault opened the front, possession of Bourlon became critical to widening and protecting the salient.
• The canal crossings: exploitation depended on getting troops and cavalry across intact routes faster than the Germans could close them.

III Corps axis: the southern/right-hand thrust drove through La Vacquerie, Ribécourt and Marcoing toward Masnières and the canal crossings.

IV Corps axis: the northern/left-hand thrust moved through Havrincourt and Flesquières toward Graincourt, Cantaing and ultimately Bourlon Ridge.

The intended exploitation therefore depended on more than punching through the first trench line. The attackers needed usable crossings, clear routes, working communications and fresh forces ready to pass through.

Order of battle — British Third Army

Third Army — General Sir Julian Byng

• III Corps — Lieutenant-General Sir William Pulteney: 12th (Eastern), 20th (Light) and 6th Divisions in the opening assault, with 29th Division in immediate support/reserve.
• IV Corps — Lieutenant-General Sir Charles Woollcombe: 51st (Highland), 62nd (2nd West Riding) and 36th (Ulster) Divisions on the northern part of the operation, with additional formations including 40th and 56th Divisions becoming involved as the battle developed.
• Cavalry Corps — Lieutenant-General Sir Charles Kavanagh: 1st, 2nd and 5th Cavalry Divisions positioned for exploitation on the opening phase.
• Tank Corps — Brigadier-General Hugh Elles: nine tank battalions committed across the assault sectors, with more than 400 tanks involved in the opening operation including fighting, supply and specialist vehicles.
• Royal Flying Corps: 14 squadrons assigned to tasks including ground attack, artillery cooperation, reconnaissance and communications.

The important point is not the headline number of tanks. Six infantry divisions formed the immediate assault across the III and IV Corps fronts. The tanks were allocated into that infantry plan rather than operating as a separate armoured army.

Order of battle — German Second Army

German Second Army — General Georg von der Marwitz

British intelligence recorded three German divisions in the line on the principal attacked front when the offensive opened:

• 20th Landwehr Division
• 54th Infantry Division
• 9th Reserve Division

They formed part of the wider Second Army defensive system around the Cambrai sector. Other formations were close enough to reinforce, and after 20 November the Germans moved divisions from other parts of the Western Front into the battle.

For the major counter-offensive on 30 November, the response was organised into larger corps-style groupings, conventionally described as Gruppe Arras, Gruppe Caudry and Gruppe Busigny. Contemporary British intelligence recorded thirteen additional German divisions being drawn into the Cambrai front after the opening attack. This distinction matters: the British did not attack eighteen waiting divisions on 20 November. The German strength grew as Second Army recovered and concentrated for its counter-stroke.

Key personalities

The plan: surprise instead of warning

Cambrai brought together ideas developed by several officers rather than belonging to one inventor. Tank Corps thinkers including J. F. C. Fuller argued for concentrating tanks on suitable ground. Hugh Elles represented the armoured force in France. Artillery planners, notably Brigadier-General H. H. Tudor, promoted methods that could achieve effective fire without the prolonged registration that normally advertised an offensive.

The result was a different opening sequence. Guns were surveyed and their fire calculated in advance. When the bombardment began, it was part of the attack rather than days of preparation. Smoke and a creeping barrage supported the advance. Tanks carried huge fascines — bundles of wood — to drop into the unusually wide Hindenburg Line trenches so other tanks could cross.

Infantry units trained with their assigned tanks. Secrecy extended to the final concentration of armour, and aircraft activity helped mask some of the noise associated with moving the vehicles forward.

20 November — the breach

The attack began at about 06:20. Across much of the front the combination of surprise, tanks and artillery worked dramatically. Hindenburg Line positions were penetrated and some British formations advanced several miles.

Results were not uniform. The 12th (Eastern) Division advanced on the right. The 20th (Light) Division pushed through La Vacquerie toward Masnières. The 6th Division took Ribécourt and Marcoing. North of them, the 51st (Highland) Division met much stronger difficulty around Flesquières while the 62nd Division made substantial progress through Havrincourt toward Graincourt.

At Masnières, a canal bridge failed under a tank, worsening the problem of moving exploitation forces across the water obstacle. At Flesquières, German guns inflicted conspicuous tank losses and the ridge delayed the northern side of the advance.

A voice from the opening day

Second Lieutenant Douglas McMurtrie of the Somerset Light Infantry recorded the attack as he saw it. One short line captures what was genuinely new about the battlefield:

“It was extraordinary watching the tanks go forward followed by the infantry.”

His diary also records the other half of the picture: German machine-gun fire recovering from the surprise, casualties appearing, aircraft moving overhead and tanks being knocked out. The technological spectacle and the human cost happened at the same time.

21–22 November — the window begins to close

Flesquières was occupied after the Germans withdrew, but the first day's momentum could not simply be recreated. The battle increasingly focused on the northern flank around Fontaine-Notre-Dame, Anneux and Bourlon.

Every hour mattered. Tanks that had survived the first day needed fuel, maintenance and crews. Infantry battalions were tired and reduced. Artillery observers and communications had to move forward. Roads and crossings became congested. German reserves were arriving.

23–27 November — Bourlon Wood

Bourlon Ridge dominated the northern side of the salient. British attacks fought into and around Bourlon Wood and Fontaine, but the terrain absorbed troops and the German defence stiffened.

Fresh British formations were committed, including the 40th Division, but the battle was no longer the clean surprise operation of 20 November. It had become another contested Western Front fight in which artillery, local counter-attacks and reinforcement decided each piece of ground.

The failure to secure and exploit Bourlon quickly was one of the central reasons the initial penetration did not become the operational breakthrough that the opening hours appeared to promise.

Why the tanks could not do it alone

Tank numbers declined rapidly through breakdown, mechanical wear, ditching and German fire. That was predictable for 1917 machinery operating over a battlefield. The more important failure was operational: the rest of the system could not always pass through the breach at the speed required.

Reserves were limited partly because major British forces remained committed elsewhere. Communications became difficult. Some formations outran effective artillery support. Cavalry exploitation was slowed by crossings, congestion and German resistance. A penetration is therefore not the same thing as a breakthrough.

30 November — the German counter-attack

German Second Army had spent ten days reinforcing and reorganising. On 30 November it struck back on a broad front.

The counter-offensive used a short, intense artillery preparation including high explosive, mortars and gas, followed by assault troops exploiting weak points rather than advancing everywhere in rigid waves. On the southern side of the salient German formations penetrated deeply, overran positions and threatened to cut off British troops farther east.

British units recovered in some sectors and the German attack eventually encountered the same problems that had limited the British: lengthening supply routes, broken communications, exhaustion and the growing difficulty of coordinating forces once the attack moved beyond the prepared system.

1–7 December — withdrawal and stabilisation

Third Army could not safely hold every piece of ground gained in the opening assault. British withdrawals shortened the salient while fighting continued around the new line. By the end of the Cambrai operations both armies retained some local gains, but neither had achieved the decisive result sought during its own offensive phase.

Chronology

Casualties

The National Army Museum gives approximately 44,000 British casualties killed, wounded or captured and about 45,000 German casualties across the operation.

Those numbers matter because the language of innovation can make Cambrai sound like a technology demonstration. It was still a large and costly battle fought by infantry, gunners, engineers, airmen, cavalry and tank crews on both sides.

What Cambrai actually proved

It did prove that a deep fortified system could be penetrated quickly through surprise and coordinated arms without the conventional days-long preliminary bombardment.

It did not prove that tanks had solved trench warfare. The tank was a component of a system. The opening success depended on artillery, infantry, engineers, reconnaissance, training and secrecy. The failure to turn the opening into a decisive result exposed communications, reserve, logistics and exploitation problems.

The German counter-attack supplied the mirror image: a well-prepared counter-stroke could recover large areas, but it too lost momentum once its own communications and supply system stretched.

That is why Cambrai belongs on the road to 1918. Both sides were learning how to create temporary operational shock. The harder problem was sustaining it.

Wear the history

The live design tied directly to this battle is the Cambrai 1917 T-Shirt — WW1 Soldier Heritage.

Explore the First World War collection →

Continue to Log 026 — Battle of Amiens 1918 →

Sources and further reading

• National Army Museum — 1917: Year of stalemate / Cambrai
• Royal Tank Regiment — Battle of Cambrai and Tank Corps order of battle
• The Long, Long Trail — Cambrai operations and British formations
• The Tank Museum — Hugh Elles and Cambrai
• The Tank Museum — Tank Corps war diaries before Cambrai
• Wikimedia Commons — public-domain United States Military Academy Cambrai map
• Wikimedia Commons / IWM — Flesquières official photograph and public-domain record

I treat Cambrai as a two-phase battle—British surprise attack and German counter-offensive—not as a tank demonstration. Tank innovation, infantry experience, artillery science, German adaptation, casualties and the failure of exploitation belong to the same story.