This entire document refers to source 2.
June 28th. Archduke Francis Ferdinand is assassinated.
July 27th. Austria-Hungary declares war on Serbia. This is considered the beginning of WW1.
August 2nd to 7th. Germany begins their Schlieffen Plan. British renforcements land in France.
August 10th. Austria Hungary invades Russia.
August. France uses tear gas for the first time.
September 9th. The Allied Powers halt Germany’s attack of France.
October 25th. The Ottoman Empire surprise attacks Russian forces in the Black sea, joining the Central Powers.$^7$
November 2nd. Russia declares war on the Ottoman Empire.$^7$
February 18th. Germany begins naval blockade against Britain.
April 25th. The Allied Powers land troops on the Gallipoli Peninsula of the Ottoman Empire.
April. Germany began use of chlorine gas.
May 7th. German forces sink the passenger liner, Lusitania, killing 128 Americans.
May 23rd. Italy declares war on Austria Hungary.
February 21st. Germany begins to attack Verdun.
May 31st. The naval battle of Jutland between Germany and Britain takes place.
July 1st. The Allied Powers begins the battle of Somme.