Tanks were first used in combat at the Battle of Flers-Courcelette on September 15, 1916, during the larger Battle of the Somme in World War I. Britain deployed 49 of its new Mark I tanks that day across the muddy, cratered landscape of northern France. The results were mixed at best, but the arrival of armored vehicles on the battlefield permanently changed the nature of warfare.
The Battle of Flers-Courcelette
Flers-Courcelette was part of the broader Somme offensive, which had been grinding on since July 1916 with devastating casualties on both sides. British commanders decided to commit their secret weapon: a new class of armored fighting vehicle that could cross trenches, crush barbed wire, and shield troops from machine gun fire. Forty-nine tanks were dispersed in small groups among the infantry divisions making the assault.
The debut was far from smooth. More than a third of the tanks broke down before even reaching their starting positions. Once the attack began, still more became stuck, stalled, or suffered mechanical failures. Only nine tanks achieved their assigned objectives. Still, those that did reach German lines had a dramatic effect, helping infantry advance and causing panic among defenders who had never seen anything like them.
Why Britain Built the Tank
By late 1914, the Western Front had settled into a deadly stalemate. Soldiers on both sides sheltered in miles of trenches, protected by barbed wire and machine guns that made open-ground attacks suicidal. Military leaders desperately needed a way to break through these defenses.
In February 1915, with the enthusiastic backing of Winston Churchill (then First Lord of the Admiralty), the British government formed the Landships Committee. This group of military engineers and officers from the army and the Royal Naval Air Service reviewed proposals for new armored vehicles that could cross the shattered terrain of no man’s land. Lieutenant Colonel Ernest Swinton had championed the concept, and development moved forward in near total secrecy.
An early prototype called “Little Willie” was built, but it was essentially obsolete before it was finished. The designers, William Tritton and Walter Wilson, had already conceived a better layout with tracks running all the way around the hull, giving the vehicle far greater trench-crossing ability. That improved design became the Mark I, the machine that would see action at Flers-Courcelette.
What the Mark I Looked Like
The Mark I was a massive, lozenge-shaped vehicle that looked nothing like modern tanks. A total of 150 were built, split evenly between two variants. “Male” tanks carried a pair of sponsons (armored compartments bolted to each side), each mounting a six-pounder cannon. “Female” tanks replaced the cannons with two heavy machine guns per sponson, intended for cutting down infantry rather than destroying fortifications.
Early Mark I models also featured a set of rear wheels on an external tail assembly. These wheels served as the primary steering mechanism, controlled by wire cables attached to a steering wheel inside the cab. With the wheels turned fully, the tank could make a circle roughly 60 feet across. The tail could also be hydraulically raised to shift the tank’s center of gravity when cresting high ridges or crossing trenches.
Conditions Inside the Tank
Riding inside a Mark I was brutal. The crew of eight shared a cramped, unventilated steel box with a roaring engine. Temperatures could exceed 40°C (104°F). Carbon monoxide fumes, petrol vapor, and gun smoke choked the air. The noise was so extreme that normal speech was impossible. The driver had to signal gear changes by hammering on the hull with a wrench so the gearsmen could hear.
Visibility was almost nonexistent. Crews peered through narrow slits that offered tiny windows onto the battlefield, and enemy bullets striking the armor sent showers of hot metal fragments spraying inside. Many early tank crewmen suffered burns, temporary deafness, and carbon monoxide poisoning even without being hit by enemy fire.
How the Germans Responded
The first tank attacks caused genuine fear among German soldiers. Some fled their positions rather than face the machines. But the shock wore off quickly. Even at Flers, German gunners discovered they could destroy tanks with field artillery, and machine gun fire and grenades could damage them at close range.
The Germans adapted fast. After Flers, they formed 50 dedicated anti-tank artillery batteries, each equipped with six field guns fitted with smaller wheels so they could be dug in and concealed more easily. They also distributed steel-cored armor-piercing bullets for their machine guns. When the Germans later captured a disabled British tank, they measured it, photographed it, removed parts for analysis, and conducted firing trials. Those tests confirmed that their armor-piercing ammunition could reliably punch through the tank’s plating.
The Germans also redesigned their defenses. Trenches in the new Hindenburg Line were deliberately widened to make them harder for tanks to cross, and Germany began work on its own tank design. Their overall assessment was that the tank was slow, poorly mobile, and highly vulnerable. When French tanks made an underwhelming combat debut in April 1917, it only reinforced that view.
Why Flers-Courcelette Still Mattered
By the cold numbers, the first tank attack was a disappointment. Most machines broke down, the territorial gains were modest, and the element of surprise was spent on a limited engagement rather than a decisive offensive. Many commanders felt the tanks had been committed too early, before enough could be built and before crews had adequate training.
But the concept was proven. Tanks could cross trenches, withstand small arms fire, and terrify defenders. Over the next two years, designs improved rapidly. By the Battle of Cambrai in November 1917, massed tank formations achieved a breakthrough that stunned both sides. And by the final Allied offensives of 1918, tanks were an integral part of combined-arms attacks that helped end the war. The clumsy, unreliable machines that lurched forward at Flers-Courcelette had, in just two years, become a weapon no modern army could do without.