One of the most potent weapons of the 20th century, the tank has evolved over many years of development. Increasingly sophisticated technology has enhanced the tank's domination of all operational conditions, by virtue of its unparalleled combination of offensive and defensive attributes. Firepower, protection and mobility have all been improved continuously in the ceaseless struggle for battlefield supremacy. The tank has a position of unrivalled importance in 20th-century military history. Developed originally by the British to break the deadlock of trench warfare during World War I, the tank proved to be a devastating breakthrough weapon. It's true potential, however, was only fully appreciated by the Germans, who set in train a highly secret tank development programme between the World Wars. This initiative culminated in the revolutionary concept of Blitzkrieg, a strategy based on the use of armour to punch holes in the enemy's defences, and was to result in the Nazi domination of continental Europe. The tank continues to be at the heart of modern strategic thinking, having proved its worth in the 1991 Gulf War.