The declaration of war was greeted with a wave of patriotic euphoria as the British Expeditionary Force left for Belgium and 2 million men volunteered.

In the summer of 1916 high hopes of a breakthrough that would end the war only ended in stalemate and tragedy.

The story of the human carnage that followed every battle and the struggle to save lives. We hear from nurses- and from men who were gassed, the shell shocked and the amputees who always remembered who saved them.

The story of 1917 and the terrible battle of Passchendaele. Many drowned in mud in battles that remains synonymous with the horror of mechanized warfare.

In spring 1918 thousands of young British conscripts were sent to France to make up the numbers. Many were taken prisoner. But by the summer the tide began to turn and the boys of 1918 helped turn defeat into victory.