The First Battle of the Marne was one of the most pivotal battles in history. Fought outside Paris in September 1914, it turned the tide of the German invasion of France, and robbed Kaiser Wilhelm II of his best chance of winning the First World War. The battle began when the French and British armies launched a massive counter-offensive, and it ended - after five, tense days of fluctuating fortunes - in a German retreat. The so-called 'miracle...