The Battle of Sheikh Sa’ad is the first attempt to relieve the besieged British in Kut, Mesopotamia. The Turkish finally withdraw but the British casualties number 4,000, a situation exasperated by the poor medical facilities.
Allied evacuation of Helles marks the end of the Gallipoli campaign.
Introducing conscription, the British Government passes the Military Service Act, due to become law on May 25.
The Battle of Verdun starts with a German offensive against the Mort-Homme Ridge. The German plan is to bleed the French dry of men and resources. The battle lasts 10 months and over a million men become casualties.
Germany declares war on Portugal. Six days later, Austria follows suit.
The Battle of Kut. The third and final Allied attempt to relieve Kut flounders in the mud along the Tigris, with 23,000 Allied casualties.
Easter Rising in Dublin.
Besieged garrison at Kut in Mesopotamia surrenders after 143 days and 3,000 British and 6,000 Indian troops go into captivity. The majority of these die of disease and starvation in prison camps.
Arabs capture Mecca from the Turks.
May 31-June 1
The Battle of Jutland. The German High Seas Fleet is forced to retire despite inflicting heavier losses on the Royal Navy (14 ships and 6,100 men), but the German fleet remains in port for the rest of the war.
The Russian Brusilov Offensive begins on the Eastern Front. It nearly cripples Austria-Hungary out of the war.
TE Lawrence aids Hussein, Grand Sharif of Mecca, in the Arab revolt against the Turks in Hejaz.
Lord Kitchener sails for Russia on board HMS Hampshire. The ship is mined off Orkney and Kitchener is lost along with 643 other crewmen and general staff.
Voluntary Enlistment in Britain is replaced by Conscription.
The opening day of the Battle of the Somme. 750,000 Allied soldiers are unleashed along a 25 mile front. By the end of the day the British sustained 57,470 casualties, of which 19,240 died. It remains the worst single day’s fighting in British military history.
The Battle of Bazentin Ridge marks the end of the first Somme Offensive. The British break the German line but fail to deploy the cavalry fast enough to take full advantage. Some 9,000 men are lost.
The Battle of Pozières Ridge marks the second Somme Offensive. Close to the highest point of the Somme battlefield, Pozières dominates the surrounding countryside. The action to take the village costs 17,000 Allied casualties, the majority of whom are Australian.
Under General Smuts, Britain enters the Morogoro Campaign in East Africa. The Germans lead a deadly guerrilla campaign, but disease kills 30 men for every one that dies in combat.
Italy declares war on Germany.
The first Zeppelin is shot down over Britain by Lt Leefe Robinson. The Royal Flying Corps uses a new combination of explosive and incendiary bullets to great effect. Robinson awarded the Victoria Cross.
The Battle of Ginchy. The British capture Ginchy – a post of vital strategic importance, as it commands a view of the whole Somme battlefield.
The Battle of Flers-Courcelette signifies the start of the third stage of the Somme Offensive. Tanks are used for the first time. Despite initial gains the Allies fail to break through German lines.
The Battle of Thiepval. Tanks play a crucial role in the capture of this strategic village.
The Battle of Ancre. The fourth phase of the Somme Offensive is marked by the British capturing Beaumont Hamel and St Pierre Divion, taking nearly 4,000 prisoners.
David Lloyd George appointed British Prime Minister.
Germany delivers Peace Note to Allies suggesting compromise.
The Battle of Verdun ends. It is the longest and costliest battle on the Western Front.