<P> In the aftermath of World War I, Greece fought against Turkish nationalists led by Mustafa Kemal, a war that eventually resulted in a massive population exchange between the two countries under the Treaty of Lausanne . According to various sources, several hundred thousand Greeks died during this period, which was tied in with the Greek Genocide . </P> <P> World War I began as a clash of 20th - century technology and 19th - century tactics, with the inevitably large ensuing casualties . By the end of 1917, however, the major armies, now numbering millions of men, had modernised and were making use of telephone, wireless communication, armoured cars, tanks, and aircraft . Infantry formations were reorganised, so that 100 - man companies were no longer the main unit of manoeuvre; instead, squads of 10 or so men, under the command of a junior NCO, were favoured . </P> <P> Artillery also underwent a revolution . In 1914, cannons were positioned in the front line and fired directly at their targets . By 1917, indirect fire with guns (as well as mortars and even machine guns) was commonplace, using new techniques for spotting and ranging, notably aircraft and the often overlooked field telephone . Counter-battery missions became commonplace, also, and sound detection was used to locate enemy batteries . </P> <P> Germany was far ahead of the Allies in using heavy indirect fire . The German Army employed 150 mm (6 in) and 210 mm (8 in) howitzers in 1914, when typical French and British guns were only 75 mm (3 in) and 105 mm (4 in). The British had a 6 - inch (152 mm) howitzer, but it was so heavy it had to be hauled to the field in pieces and assembled . The Germans also fielded Austrian 305 mm (12 in) and 420 mm (17 in) guns and, even at the beginning of the war, had inventories of various calibres of Minenwerfer, which were ideally suited for trench warfare . </P>

What was the name of the major war when did it start when did it end