Sequencing Events in the order in which they occurred, starting with the earliest and finishing with the event that happened last. (Hint: Go through the list first, writing in the dates behind the event. This will help you see the order more clearly.)

The Triple Alliance and the Triple Entente are established.
Germany invades Belgium, violating a treaty guaranteeing Belgium’s neutrality.
The Ottoman Empire joins the Central Powers in war.
Great Britain declares war on Germany.
Germans first use poison gas, a new and devastating weapon, against the Allied forces.
The French launch a major offensive—the Battle of the Somme.
Gavrilo Princip and the nationalist group, the Black Hand, plot to advance the cause of the
unification of Slavic peoples.
The British and the French armies stop the German advance on Paris at the Marne River,
just a few miles east of the city.
Austria-Hungary declares war on Serbia.
Archduke Franz Ferdinand, heir to the throne of Austria-Hungary, is assassinated.
The Germans launch a major offensive—the Battle of Verdun.
Germany declares war on Russia.
Germany challenges British naval supremacy in Europe.
Japan, a rival of Germany in Asia, joins the Allies in war.
Germany declares war on France.