In 1914 a series of complicated and tragic events saw Russia and Germany embark on a war that was to engulf the whole of Europe and be labelled by history as World War I. A tangle of international treaties that bound the major powers meant that, once started, widespread conflict was inevitable and on the largest and most costly scale yet seen by a modern Europe. For Russia, humiliated by defeat after defeat, the price was too high. Civic unrest forced the abdication of the Tsar and paved the way for the Bolsheviks to seize power. This is a concise guide to a complicated chapter in World War I history.