A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility and tactical offensive and defensive capabilities. Firepower is normally provided by a large-caliber main gun in a rotating turret and secondary machine guns, while heavy armour and all-terrain mobility provide protection for the tank and its crew, allowing it to perform all primary tasks of the armoured troops on the battlefield.

Tanks were first introduced by the British during World War I as a means to break the deadlock of trench warfare. They were first deployed at the Battle of Somme in limited numbers. During construction, to conceal their true identity as weapons, they were designated as water carriers for the Mesopotamian campaign and referred to as "tanks" (as in water tank).

Interwar developments in both design and tactics culminated in important concepts of armoured warfare which persist to this day and were prominently displayed during World War II. The Soviet Union introduced T-34, widely considered to be the best tank in service throughout the war and forerunner to the main battle tank. Germany introduced blitzkrieg, a strategy which makes use of massed concentrations of tanks supported by artillery and air power to break through the enemy front to surround enemy forces and accomplish objectives.

Today, tanks seldom operate alone, as they are organised into armoured units which involve the support of infantry, who may accompany the tanks in armoured personnel carriers or infantry fighting vehicles. They are also usually accompanied by aircraft of either reconnaissance or ground attack configuration.

Due to its formidable capabilities and versatility the battle tank is generally considered a key component of modern armies. However, the prevalence of unconventional and asymmetric warfare have put into question the utility of the armoured force. Ongoing research and development attempts to equip the tank to meet the challenges of the 21st century.

History

main: Tanks in World War I

Apart from Leonardo da Vinci's drawing of a round, tank-like armoured wagon, the first description of a tank-like vehicle and its usefulness in trench warfare is found in an H.G. Wells short story, "The Land Ironclads", in the Strand Magazine, December 1903. Some eight years later, in 1911, the first two practical tank designs were developed independently by Austrian engineering officer Günther Burstyn and Australian civil engineer Lancelot de Mole.

Burstyn designed his tank with a sprung suspension and armed with a single gun located in a revolving turret - a design quite similar to modern tanks - but he was unable to design a track that could carry the weight of the vehicle and propel it at reasonable speed. He submitted his idea of a "land torpedo boat" to the Military Technical Committee in Vienna but the idea was rejected as lacking sufficient merit; he did, however manage to patent his invention (Zl. 252 815 DRP).