WWI Timeline


Assassination of Austria-Hungary Archduke

June 28, 1914

Archduke Franz Ferdinand of Austria-Hungary is assassinated by Gavrilo Princip

Austria-Hungary declares war on Serbia

July 28, 1914

Austria-Hungary declares war on Serbia in retaliation of the assassination

First use of poisonous gas

April 22, 1915

150 tons of chlorine gas were deployed in Ypres, Belgium. This was the first instance of chemical warfare.

British Lusitania Sinking

May 7, 1915

German U-Boat sinks the British Lusitania, causing the death of 1198 including 128 Americans

US Declares War on Germany

6 April 1917

Germany renewed its policy of submarine warfare that it had abandoned in 1915 after the sinking of the Lusitania. All ships trading with Britain would be targeted by German submarines, which included US ships as well. The United States decided to retaliate

Hundred Days Offensive

August 8, 1918 - November 11, 1918

A series of assaults against the Central Powers starting from August 8th to November 11th.


November 11, 1918 - December 11, 1918

Germany is required to surrender several military units and their areas of occupation in East Africa are to be abandoned. Everyone must participate in a 30-day cease fire

Treaty of Versailles

June 28, 1919

The Treaty of Versailles was the treaty that ultimately ended the state of war between the Allies and Germany, thus ending WWI



July 28, 1914 - June 28, 1919