In June 1914, Franz Ferdinand, an Austrian archduke and heir to the Austro-Hungarian throne was assassinated by Serbian nationalist. The Austrians outraged and invaded Serbia with the approval and support of German Kaiser. Germany entered into World War I on August 1, 1914, by sending its main armies through Belgium to attack Paris.

These colorized photographs by Duriez Frederic show German soldiers in the battlefields of the Great War.

Also check, French soldiers during WWI .