A summary of world war I
Continual trouble in the Balkans led to the formation of several complicated military alliances throughout Europe. The continent was eventually split into two groups. Britain, France and later Russia joined to form the Entente Cordiale, while Germany, Austria-Hungary and Italy formed the Triple Alliance.
In 1914 Archduke Franz Ferdinand of Austria-Hungary was assassinated in Serbia, activating the alliance agreements.
First Austria declared war on Serbia, Russia sided with Serbia, and then Germany declared war on Russia. Germany invaded Belgium, bringing the British and French into the conflict.
This was the first mechanized war in history. Aircraft were used for the first time to observe the enemy and to locate suitable targets for long-range artillery. There were fighter planes, Zeppelin airships were used for bombing, tanks made their first appearance and there was this terrifying new weapon called poison gas.