-
Archduke Francis Ferdinand is assassinated.
-
Austria-Hungary declares war on Serbia, beginning World War I.
-
Allied forces halt German advance into France during First Battle of the Marne.
-
Italy declares war on Austria-Hungary.
-
Allied offensive begins the Battle of the Somme.
-
The United States declares war on Germany.
-
Russia signs the Treaty of Brest-Litovsk with Germany.
-
Germany signs the Armistice at Compiègne, ending World War I.