British tanks of the Mark I variety made their debut during World War I. Designed to burst through enemy lines and provide cover for advancing forces, it was a direct response to the trench warfare that defined the conflict on the Western Front. The Mark I used a steam engine for propulsion and was armed with machine guns and cannons. Its protection from small weapons fire was greatly enhanced by the hardened steel plates that made up its armor. Yet it moved slowly and couldn't go very far, leaving it open to artillery and anti-tank fire. Even with its shortcomings, the Mark I was a major step forward in the evolution of armored warfare, and its deployment cleared the way for the creation of more sophisticated tanks in the decades to come.

The Mark II was a modification of the British tank that saw service in WWI. It was superior to the Mark I in every way, including power, protection, and firepower. It was also more stable and manageable thanks to an improved suspension system. For the British, the Mark II proved to be a game-changer at the Battle of Cambrai in November 1917, when it was utilized to successfully breach enemy lines. In later conflicts, like as August 1918's Battle of Amiens, the tank played a crucial role in leading the Allied assault. While other tanks would eventually improve upon its design, the Mark II was a significant milestone in the evolution of armored warfare.

British forces utilized the Mark III tank during World War 1. It had greater armor and a more powerful engine than the Mark I and Mark II before it. It took eight people to operate the Mark III and they had to carry its 28 tons of weight. It had four machine guns and two 6-pounder guns. The Mark III was used in various pivotal conflicts throughout the war. They included Arras and Passchendaele. The Mark III was improved over its predecessors, but it was still hampered in various ways. Yet, it was a major step forward in armored warfare and inspired subsequent tank designs.

During World War I, the British utilized the Mark IV tank, which had been created to address the problems of earlier models. It had around 28 tons of weight and was armed with six 6-pounder guns and several machine guns. The Mark IV could reach a top speed of 4 miles per hour and required a crew of eight to operate. Its effectiveness in breaching enemy lines was demonstrated for the first time in 1917 during the Battle of Cambrai. The Mark IV was vulnerable to enemy fire and difficult to maneuver on the battlefield because of its design shortcomings, such as its limited mobility and unstable tracks. In spite of its flaws, the Mark IV tank was a major step forward in military technology and paved the way for the creation of even more sophisticated tanks in the future.

During World War I, the British military created a medium-sized tank called the Whippet. The designers prioritized speed and maneuverability, therefore it can reach speeds of up to 8 mph. There were three people in the tank's crew and four machine guns at their disposal. The Whippet was deployed extensively toward the end of the war, and it was very successful at penetrating enemy lines and taking advantage of front-line openings. To support infantry and other tanks, it could swiftly move across the battlefield because to its speed and agility. Whippets were used during the Hundred Days Offensive in 1918, contributing to Allied wins. Nonetheless, it was easily destroyed by anti-tank guns, resulting in significant casualties in some battles. The Whippet, in general, was a significant addition to the British armored troops during World War I and a precursor to subsequent tank designs.

The Schneider CA1 was the first French tank to see action during World War I. To aid the soldiers and smash through the German trench lines was its primary purpose. The tank had a 75mm cannon, 8mm Hotchkiss machine gun, and a 65 horse power engine. The total weight of the Schneider CA1 was roughly 13 tons, and it carried a crew of eight. Small weapons fire was well deflected by the tank's strong armor, but it was no match for anti-tank guns or artillery. The Schneider CA1 tank had its flaws, but it saw action in several battles during the war and laid the path for improved designs.

During World War I, the French army deployed a powerful tank called the Saint-Chamond. It was planned to let the French troops get around the German trenches and other defenses that had been a major hindrance. The tank had an engine that produced 90 horsepower and weighed about 23 tons. Both its heavy armor and its armament of two 75mm cannons and six machine guns made it a formidable opponent for the German army. Mechanical issues hampered it, and it ultimately failed to compete with the lighter, more adaptable Renault FT tank. However, the Saint-Chamond saw action in several pivotal conflicts during the war, notably the Battle of Soissons and the Second Battle of the Marne.

The Renault FT, or FT-17, was a French light tank that was instrumental in the war. It was the first tank to feature a turret that could rotate 360 degrees, giving it a decisive advantage over its competitors. The French military used the Renault FT for reconnaissance, infantry support, and offensive missions. It possessed strong armor and a large cannon, making it a dangerous foe in battle. Having a tank that could easily navigate and traverse rough terrain was a huge help in the trenches. Modern tanks can trace their lineage back to the Renault FT, usually considered one of the most successful tanks of World War I.

During World War I, the Russian military deployed the armored vehicle known as the Russo-Baltique. It was created by the pre-war luxury automotive manufacturer Russo-Baltique. With its 7.62 mm machine gun and 4-cylinder engine, the Russo-Baltique could travel at speeds of up to 40 kilometers per hour. Armor on the vehicle was up to 7 mm thick and constructed of steel. The Russo-Baltique saw combat on both the Eastern and Western fronts, serving mostly in reconnaissance and patrol roles. Unfortunately, the Russo-Baltique quickly became obsolete because to its low production numbers and the rapid speed of technological innovation throughout the war.

In World War I, there was no such thing as an Austin-Putilov, although the Russian Empire did use Putilov-Garford armored cars. Together, the American Garford Motor Vehicle Company and the Russian Putilov factory created the Putilov-Garford. A 3.7-inch (94mm) cannon and a machine gun were mounted on top of the 4x2 wheeled armored vehicle. In addition to its use for reconnaissance and convoy protection and infantry support, the Putilov-Garford saw combat on the Eastern and Caucasian fronts of the war. Despite its usefulness, manufacturing was restricted because of the war's impact on the availability of key inputs.

The M1917 was a bolt-action rifle used by the United States during World War I. It was also known as the American Enfield. The Springfield M1903 it was meant to replace was unable to be mass-produced fast enough to support the war effort, therefore this new model was created. In essence, the M1917 was a reworked British Enfield rifle that was adapted to fire the.30-06 Springfield cartridge. The rifle's dependability and precision won over the hearts of American soldiers. The American military deployed it in numerous conflicts, most notably the Meuse-Argonne Offensive of 1918. In addition to its use by American forces in World War II, the M1917 saw service in the Korean War as a sniper rifle in the hands of the United States Marine Corps.

Italian heavy tank production began with the Fiat 2000, which saw service in World War I. Armoured and armed with a 65mm cannon and four machine guns, it was one of the first tanks employed by the Italian army. It was vulnerable to enemy fire because of its slow speed and awkward design. Only two tanks were actually used in combat by late 1917, hence its impact on the Italian front was minimal. Notwithstanding its flaws, the Fiat 2000 was crucial in advancing Italy's armored warfare capabilities and setting the way for later, more modern tanks.

In World War I, the Germans deployed the A7V tank, one of the earliest tanks ever built. This strongly fortified vehicle had a top speed of 10 km/h, was mounted with six machine guns, and one 5.7 centimeter cannon. During the Battle of Villers-Bretonneux, for example, the A7V was utilized to great effect, destroying multiple British tanks. Only 20 A7Vs were ever made, and they were plagued with technical issues that prevented them from playing a major role in the war's result.

During World War I, the Germans considered developing a super-heavy tank called the K-Wagen. The idea behind it was to strike fear into the hearts of the enemy's ranks as part of breakthrough operations. The K-Wagen was planned to have six cannons, multiple machine guns, and two flamethrowers, with armor that would be nearly impossible to breach. Two prototypes were actually constructed, although they were never used in combat. The K-Wagen was a poorly designed, cumbersome, and unwieldy tank that proved useless on the battlefield. Though it was ultimately unsuccessful, the K-Wagen was instrumental in the evolution of modern tanks, and many of its ideas were incorporated into subsequent tank models.