A look at the major events of the conflict in May 1917:
The Polish Council of State present their demands to the Central Powers regarding the creation of an independent Poland.
The first USA destroyer flotilla arrives at Queenstown in Cork, Ireland
The Third Battle of the Scarpe and the Second Battle of Bullecourt begin during the Arras Offensive.
French forces capture Craonne on the Chemin des Dames ridge.
A major military engagement is fought between the forces of the Central Powers and the Entente near Vardar as part of the Allied Spring Offensive. It is designed to break the stalemate on the Macedonian front.
With support from Australian troops the British seize part of Bullecourt.
Germans recapture Fresnoy on the Arras Front.
French, Russian and Serbian troops launch a coordinated offensive in Macedonia which is repulsed by Bulgarian and German defenders.
Major General John J Pershing is appointed to command the United States Expeditionary Force.
British and French war commissioners parade down Fifth Avenue in New York to celebrate the USA entering into the war. The slogan “Show Your Colours” brings out a patriotic show of Union Jacks, Tricolores and Stars and Stripes flags.
The Tenth Battle of the Isonzo begins when, once again, Italian and Austro-Hungarian troops fight along the banks of the Isonzo river.
German Zeppelin L22 is destroyed in the North Sea by a H.12 British flying boat during a reconnaissance mission near Terschelling Bank flown by Lt. Galpin and Sub-Lt. Leckie.
Fourteen British drifters (boats built along the lines of commercial fishing drifters but fitted out for naval purposes) are sunk in the Otranto Straits when British and Austrian naval forces clash.
Philippe Petain replaces Robert Nivelle as Commander-in-Chief of the French Army. His task is to turn back the imminent German offensive and quell the mutinies currently ongoing in the French army.
Honduras severs diplomatic relations with Germany.
The Compulsory Service Act becomes law in the USA, requiring all American men aged between 21 – 30 to register for the draft.
The United States Government announces it will send a Dision of the US Army to France.
French Commander-in-Chief Philippe Petain succeeds in bringing the mutinies within the French army to an end.
British troops capture the Siegfried line from Bullecourt to one mile east of Arras.
Brigadier-General Nash succeeds Sir Eric Geddes as Director-General of Transportation.
Count Istvan Tisza resigns as Prime Minister of Hungary.
The British Royal Navy introduces a newly created convoy system ensuring all merchant ships crossing the Atlantic ocean will now travel in groups under the protection of the British Navy.
Heavy casualties are sustained in a German aeroplane raid on Folkstone, Kent on the south-east coast of England.
HMS Dover Castle is torpedoed and sunk by the German submarines UC-67 in the Mediterranean, en route from Malta to Greece.
An Anglo-French conference in London discusses the deposition of King Constance of Greece and considers the occupation of Athens and Thessaly.
The French liner SS Yarra is torpedoed and sunk by the German submarine UC-74 near Kreta in Greece.
The South African military commander General Jacob van Deventer succeeds Major-General Reginald Hoskins in command of the British Forces in East Africa.