January 8 – Gallipoli campaign ends.
January 24 – Government passes the Military Service Act which introduced conscription. This to become law on May 25.
February 21 – The Battle of Verdun starts, which lasts 10 months and had over a million casualties.
March 9 – Germany declares war on Portugal.
May 31 and June 1 – Battle of Jutland. The Royal Navy loses 14 ships and 6,100 sailors.
June 5 – Lord Kitchener sails for Russia aboard HMS Hampshire, but the ship sinks after hitting a mine off Orkney.
June 8 – Compulsory enlistment introduced in Britain.
July 1 – The Battle of the Somme. 60,000 (out of a total of 75,000) are killed, injured or missing by the end of the day. This is the worst single day’s fighting in British military history.
August 28 – Italy declares war on Germany.
September 2 – The first Zeppelin is shot down over Britain.
September 15 – Tanks are used for the first time at the Battle of Flers-Courcelette.
December 7 – Lloyd George becomes Prime Minister, replacing Asquith.
December 18 – The battle of Verdun ends.