For four years, the great European powers fought a gruesome battle. In response, Austria-Hungary set Serbia an ultimatum. If Serbia failed to meet its demands, the Austro-Hungarian army was going to invade Serbia.
The Serbs accepted all demands, except one. They wanted to investigate the murder themselves, without interference from the Austro-Hungarian representatives. Austria-Hungary did not agree and on 28 July declared war on Serbia. The fact that this crisis resulted in a world war was due in part to the alliances between the various European countries.
As many states were bound by treaties to help one another in the event of war, there were two camps: the Central Powers Austria-Hungary and Germany and the Allied Powers France, Russia and England.
Both sides expected the war to be over soon, but they were wrong. The First World War lasted four years, and millions of soldiers from all over the world were killed. In August , Otto Frank went into the German army. He was trained as a gunner. From the autumn of onwards, he was stationed at the Western Front.
He was part of a so-called Lichtmesstrupp : a unit that detected and calculated the location of enemy guns and passed information about the trajectory on to the artillery. In , he took part in the Battle of the Somme, in which almost half a million German soldiers were killed. A year later, Otto was promoted to sergeant and the year after that to officer candidate. Otto's brothers Herbert and Robert served in the German army as well.
