Timeline of World War I (Age of Kings)

This page is a chronology of events that take place during World War I. These events may be martial, political, or economic in nature. They are placed here apart from the complete timeline because of the many important events during the war.

1914

 * 28 July - Austria-Hungary declares war on Serbia. Russia orders mobilization.
 * 1 August - Germany mobilizes and declares war on Russia in response to its mobilization. France orders mobilization as well.
 * 2 August - German troops occupy Luxembourg.
 * 3 August - Germany declares war on France. Belgium refuses ultimatums from Germany to allow safe passage of German troops.
 * 4 August - German troops invade Belgium. The United Kingdom declares war on Germany in response.
 * 6 August - Austria-Hungary declares war on Russia.
 * 12 August - The United Kingdom declares war on Austria-Hungary.
 * 20 August - German troops occupy Brussels.
 * 23 August - Japan declares war on Germany.
 * 26 August - The German colony of Togoland surrenders to Britain and France.
 * 30 August - The Battle of Tannenberg concludes in a German victory over Russia.
 * 1 September - Saint Petersburg is renamed to Petrograd.
 * 5 September - The First Battle of the Marne occurs.
 * 13 September - South African forces begin hostilities with Germany's South West Africa colony
 * 15 September - The Maritz Rebellion of disaffected Boers against the government of the Union of South Africa begins.
 * 9 October - Antwerp falls to the Germans.
 * 29 October - Ottoman ships shell Austro-Hungarian ports.
 * 30 October - Germany and Austria-Hungary declare war on the Ottoman Empire.
 * 7 November - The German colony of Tsingtao falls to Japan and Britain.
 * 8 December - A British squadron defeats the entire German East Asia Squadron at the Battle of the Falklands.
 * 24 December  - An unofficial, temporary Christmas truce begins, between British and German soldiers on the Western Front.

1915

 * 31 January - German forces first use poison gas at the Battle of Bolimów against the Russians. However, the fas is ineffective because of freezing temperatures.
 * 4 February - The Maritz Rebellion of Boers against South Africa ends in defeat.
 * 22 April - German forces use poison gas at the Second Battle of Ypres, the first use of gas on the Western Front.
 * 26 April - Italian, German, and Austro-Hungarian diplomats sign the Treaty of Trento. Italy promises to join the Central Powers in exhange for certain concessions from Austria-Hungary and territorial gains from the Allies.
 * 1 May - German South West Africa is occupied by South African forces.
 * 15 May - Austria-Hungary transfers the region of Trentino and portions of the Austrial Littoral to Italy along with a payment of two million Krone.
 * 24 May - Italy joins the war on behalf of the Central Powers be declaring war on France.
 * 30 May - Italian campaigns begin in British Egypt and French Tunisia. French Somaliland is occupied.
 * 15 June - Italy withdraws from its unsuccessful Egyptian campaign.
 * 22 July - Russian forces stage the "Great Retreat" and withdraw from Russian Poland.
 * 12 August - British forces have occupied all of Italian Somaliland.
 * 6 September - Britain begins testing its first "Tank" prototypes.
 * 7 October - Austria-Hungary and Germany begin the last phase of the Serbian campaign.
 * 9 October - Belgrade falls to the
 * 14 October - Romania joins the war on the side of the Central Powers, invading Serbia.
 * 20 October - Serbia is completely occupied by Central forces.
 * 15 November - Bulgaria joins the war on the side of the Allies.
 * 20 November - Austria-Hungary and Italy launch an invasion of Montenego.
 * 24 November - Russian, Ottoman, and Bulgarian forces invade Romania, causing massive casualties and prompting immediate Central reinforcement.
 * 4 December - Montenego is completely occupied by Central forces.