World War I involved 32 nations from 1914 to 1919. It redrew the world map and reshaped many borders in Europe. The collapse of the Russian Empire created Poland, the Baltics, and Finland.

When Gavrilo Princip assassinated Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne, on June 28, 1914, few could have known it would reverberate for four years of brutal war ...