It was World War 1 that introduced the mighty 'tank' to the battlefields of Europe and set the stage for the great clashes of the 20th Century to follow.
World War 1 had roots in the century before and the industrialization of Europe soon pushed the various alliances to total conflict in the summer of 1914. The battlefields soon turned to red and booged down in the bloody fighting centered on 'trench warfare'. To get beyond the impass, a myriad of developments soon moved armies back and forth and powers jockeyed for the advantage. Among the creations in ground warfare were the armored car, massive artillery guns and - of course - the combat tank.
These steel beasts were nothing in comparison to the sleek, fast-moving systems we see today; they were lumbering monsters that could be done in as easily by a trench or artillery shell as it could fire from a mine. The systems were, for the most part, cumbersome and stepping stones to the developments witnessed in World War 2 decadeslater. Nevertheless, The Great War was the birthplace of the tank and the first tank-versus-tank duel was recorded there between Germany and Britain, the results proving inconclusive. Beyond that, railways were at the heart of moving men and machines with massive railguns developed in the latter. Artillery also reigned supreme over the battlefield and were the constant bane of any one offensive.
In the end, the war was decided by manpower and sheer will with the Central Powers, led by the German Empire, ultimately capitulating in 1918.