The Great War as it came to be known was the first truly global conflict, and changed the course of world history. When World War I began in 1914, both sides had anticipated a swift and decisive victory, but the war quickly bogged down into a stalemate. The Western Front extended from the English Channel in the north to the Swiss border in the south, covering approximately 700 kilometers (about 440 miles). Some of the major battles fought on the Western Front include the Battle of the Marne, the Battle of Ypres, the Battle of the Somme, and the Battle of Passchendaele. There were massive casualties and little territorial gain. This illustrated book examines this brutal conflict in detail. It looks at why war broke out, and how technology and tactics developed throughout the conflict determined which battles were won and lost, including trench warfare, gas, tanks, aircraft, submarines and the development of a new fire power.