World War I

Proper noun

Proper noun World War I

World War I.

1. (history) World War I was a war from 1914 to 1918 between countries including, on one side, the United Kingdom, France, Serbia, the Russian Empire, Italy, the United States, Japan, Belgium, and other Allied Nations, and, on the other side, the German Empire, Austria-Hungary, the Ottoman Empire, and Bulgaria.

   The First Battle of the Marne was part of World War I.