The Mark I tank is a British tank, often classified as a WW1 heavy tank. The first prototypes of this car appeared in 1916, and serial production started in the same year. The car was powered by a single carburettor engine with a capacity of up to 105 HP. The length of the vehicle was 7.93 meters with a total width of 4.19 meters. The armament of the vehicle (in the so-called Male version) consisted of two 57 mm cannons and three machine guns, while the so-called female version - five machine guns. The Mark I tank was the first British tank of the Great War to be used extensively and the first tank used in combat in history! It was developed on the basis of the assumptions and conclusions drawn from the operation of the prototype Little Willie tank. At the same time, however, it clearly differed from it in the location of the tracks or the shape of the hull, although it was powered by the same engine. The Mark I tank also introduced a rhomboidal shape typical of British tanks of 1916-1918. The vehicle did not have a turret, and all the armament was mounted on sponsons on the sides of the tank. The Mark I was first used in combat in September 1916 at the Battle of the Somme.The Mark V tank is a British tank, often classified as a WW1 heavy tank. The first prototypes of this car appeared at the end of 1917, and serial production started at the turn of 1917-1918. As a result, about 400 tanks of this type were created. The car was powered by a single Ricard engine with a capacity of up to 150 HP, and its weight reached 30 tons. The armament of the vehicle (in the so-called Male version) consisted of two 57 mm cannons and three machine guns, while the so-called female version - five machine guns. The so-called Composite (or Hermaphrodites) version armed with a single 57mm cannon and four machine guns. The Mark V was developed on the basis of the Mark IV tank. From its predecessor, it took over the main design assumptions, such as the diamond shape of the hull and tracks, the lack of a turret with armament and its placement in sponsons on the sides of the wagon. However, it received a new drive unit and, what is equally important, a different drive train and a track turning mechanism. There was also an observation tower for the commander of the car. The tank was also much more mechanically refined than its predecessor, and its armor thickness varied from 6 to 14 millimeters. Mark V tanks were used in combat for the first time at the Battle of Hamel in July 1918. They were also used extensively at the Battle of Amiens in August 1918. Interestingly, they were definitely withdrawn from the British Army only in the early 1930s!The Mark II tank is a British tank, often classified as a WW1 heavy tank. The first prototypes of this car appeared in 1916, and serial production continued at the turn of 1916-1917. As a result, 50 tanks of this type were created. The car was powered by a single carburetor engine with the power of 105 HP, and its weight ranged from 27 to 28 tons. The armament of the vehicle (in the so-called Male version) consisted of two 57 mm cannons and three 8 mm Hotchkiss machine guns, while the so-called Female version - five machine guns, including one 8mm Hotchkiss and four 7.7mm Vickers. The Mark II was developed on the basis of the Mark I tank. From its predecessor, it adopted the main design assumptions, such as the diamond shape of the hull and tracks, the lack of a turret with armament and its placement in sponsons on the sides of the vehicle. At the same time, from the very beginning, it was assumed that the Mark II would be primarily intended for training tasks, as well as introducing numerous, though rather minor, mechanical improvements resulting from the use of Mark I vehicles. The training courses were used in the Battle of Arras in April and May 1917, but suffered heavy losses.The Mark IV tank is a British tank, often classified as a WW1 heavy tank. The first prototypes of this car appeared in 1917, and serial production continued in 1917-1918. As a result, about 1,220 tanks of this type were created. The car was powered by a single Daimler-Foster engine up to 105 HP, and its weight ranged from 27 to 29 tons. The armament of the vehicle (in the so-called Male version) consisted of two 57 mm caliber cannons and three 7.7 mm Lewis machine guns, while the so-called the female version - five 7.7 mm Lewis machine guns. The Mark IV was developed on the basis of the Mark I tank. From its predecessor, it adopted the main design assumptions, such as the diamond shape of the hull and tracks, the lack of a turret with armament and its placement in sponsons on the sides of the vehicle. The main modernization concerned a significant reinforcement of the armor and the placement of the fuel tank in a different part of the vehicle. The car was also generally more mechanically efficient and less reliable than its predecessor. Some vehicles of this type were also equipped with radio stations and mortars. It is also worth adding that the production of Mark IV tanks was several times greater than that of Mark I vehicles, which meant that it was divided between six production plants, with the main producer being the Metropolitan plant. Mark IV tanks were used in combat for the first time during the Battle of Messines in the summer of 1917.