The 1917 Great War Timeline by Barbara Taylor

January 19
British cryptographers decipher a telegram from German Foreign Minister Arthur Zimmermann to the German Minister to Mexico, von Eckhardt; offering United States territory to Mexico in return for joining the German cause. This message helped draw the United States into the war.
January 31
Germany announces the continuation of unrestricted submarine warfare, hoping to starve Britain into submission.
February 3
The United States severs diplomatic relations with Germany as U-Boats threaten US shipping.
February 21
The Great German Withdrawal begins. They will evacuate Serre, Miraumont, Petit Miraumont, Pys and Warlencourt, falling back 25 miles to establish stronger positions along the Hindenburg Line.
February 24
Turkish retreat to Baghdad, abandoning Kut in Mesopotamia.
MARCH 1917
March 8
First Russian Revolution begins with strikes, demonstrations and mutinies in Petrograd.
March 11
Turkish retreat to Baghdad, abandoning Kut in Mesopotamia.
March 15
Tsar Nicholas II abdicates (also for his son) as Moscow falls to Russian Revolutionaries. Demise of the Russian Army frees German troops for the Western Front.
March 26
The First Battle of Gaza, Palestine, as the British attempt to cut off the Turkish forces in Mesopotamia from their homeland. They fail to take the town and are forced to withdraw.
APRIL 1917
April 6
US declares war on Germany. Troops begin to mobilise immediately.
April 9
The Battle of Arras. The British successfully employ new tactics of creeping barrages, the ‘graze fuse’ and counter battery fire. Significant feature of Vimy Ridge captured by the Canadians during this battle.
April 16
The Second Battle of Aisne begins as part of the ‘Nivelle Offensive’. Losses are horrendous, triggering mutinies within the French Army.
April 19
The Second Battle of Gaza begins in Palestine. The plan consists of nothing more than to throw troops against well prepared Turkish positions. It is eventually called off due to mounting casualties.
MAY 1917
May 7
Captain Albert Ball RFC shot down and killed.
Posthumously awarded the VC.
JUNE 1917
June 7
The Battle of Messines Ridge. The British take the ridge with few casualties, as it is preceded by the detonation of 19 mines under the German front lines. The explosions are reportedly heard in southern England.
June 13
Germans launch the first major heavy bomber raid over London. Bombs dropped from 18 Gotha GV aircraft kill 162 people and injure 432.
June 25
First US troops arrive in France.
JULY 1917
July 16
TE Lawrence and the Arabs liberate Aqaba in Jordan after crossing the Nefu desert, which in turn assisted with the capture of Damascus.
July 24
Mata Hari stands trial for espionage.
July 31
The Third Battle of Ypres begins along a 15 mile front in Flanders. Initial attacks are successful as the German forward trenches are lightly manned.
August 15
The Battle of Lens (Hill 70). Canadian troops are in the vanguard of this assault. Hill 70 is only 15 feet higher than the surrounding landscape but it dominates the battlefield. The Canadians take and hold it against five German counter attacks. Allies lose 9,200 men.
August 20
The Third Battle of Verdun begins. French progress is marked by gaining lost territory in the earlier battles.
September 20
The Battle of the Menin Road.
September 26
The Battle of Polygon Wood.
October 1917
October 12
The British launch their latest assaults at Ypres against the Passchendaele Ridge. New Zealand and Australian divisions in the vanguard of the attack take terrible casualties, then are bogged down in the mud and are forced back to their start lines.
October 15
Mata Hari executed
October 19
The last airship raid on Britain is carried out by 11 Zeppelins.
October 24
Joint attack of Austro-Hungarian/German armies launched at Caporetto against Italian army, who are severely overwhelmed. Allies now give significant support with the dispatch of both French and British divisions.
October 25
The Second Battle of Passchendaele begins with 20,000 men of the Third and Fourth Canadian Divisions advancing up the hills of the salient. It cost the Allies 12,000 casualties for a gain of a few hundred yards.
October 30
Reinforced with the addition of two British divisions, a second offensive is launched in torrential rains to capture Passchendaele. The Allies hold the town for the next five days in the face of repeated German shelling and counterattacks.
October 31
Battle of Beersheba, Palestine. British forces take the town capturing 1,800 Turkish troops. This leaves the way open for the advance on Jerusalem.
November 7
The second Russian revolution results in the Bolsheviks under Lenin taking over. Known as the October Revolution as Russia operating the Julian calendar until February 1918. British capture Gaza.
November 10
Battle of Passchendaele ends. After months of fighting, the Allies have advanced only 5 miles, but have taken the high ground that dominates the salient. Half a million men are casualties, of which around 140,000 have been killed.
November 20
The Battle of Cambrai begins, using significant numbers of British tanks for the first time; combined with a predicted artillery bombardment. During the attack, the RFC drop bombs on German anti-tank guns and strongpoints to clear a path for the Allied tanks and ground troops. It is an early example of the ‘Blitzkrieg’ tactics used by the Germans so in the Second World War. Church bells were rung in Britain.
December 11
Britain liberates Jerusalem, ending 673 years of Turkish rule.