A lot of Europian countries took part in the Great War. All Europian continant was involved in it. How many people lived in each of those countries. All countries were "defending their homeland". Everybody wanted to save their families lives. Millians of fathers, brothers, sons, and grandfathers died protecting their home. They wanted a peaceful life for their children. The were dieing for happiness.
After 16000000 millions of people died there, most of them were men, the population definatly decrease very much. A lot of families lost their members. This war changed destiny of everybody`s life.