-
Austria-Hungary declares war on Serbia
-
-
•August 1 -- Germany declares war on Russia
-
•August 3 - Germany declares war on France
-
•August 4 - The United Kingdom declares war on Germany, after Germany invades Belgium.
-
•August 6 - Austria-Hungary declares war on Russia and Serbia declares war on Germany
-
•August 26 - The Battle of Tannenberg begins
-
•September 5 - The First Battle of the Marne begins. Trench warfare begins as soldiers on both sides dig in.
-
•October 19 - Battle of Ypres begins
-
•November 3 - The United Kingdom announces that the North Sea is a military area, effectively creating a blockade of goods into Germany
-
•April 22 - The Second Battle of Ypres begins. It is during this battle that the Germans first use poison gas