We’ve distilled 10 facts in 10 different topics to compile this giant collection – they fit together to explain some of the key causes, battles, social changes and more to give an overview of the devastating conflict. We’ve also recently published 30 Graphics That Explain the Last 100 Years alongside this list.
Build Up to World War One
1. In 1914 Europe was divided between two major alliance systems – the Triple Alliance and the Triple Entente
The Triple Entente consisted of France, Russia and Great Britain, while the Triple Alliance included Germany, Austria-Hungary and Italy. However, once war broke out Italy reneged on its commitment. See more at 5 Major Treaties & Alliances in the Build Up to World War One.
2. Britain and Germany were engaged in a naval arms race in the early 20th century
But by 1914 it was all but over: Britain had 38 dreadnoughts and dreadnought battle cruisers to Germany’s 24.
3. The combined Russian & French peacetime armies in 1913-14 had 928,000 more troops than Germany & Austria Hungary
If Britain’s peacetime force of 248,000 is also included, the Triple Entente had a significant manpower advantage over the Dual Alliance.
4. After two Balkan wars in 1912 and 1913, Serbia emerged as an empowered, nationalistic state
Serbia’s pan-Slavic intentions ran counter to Austro-Hungary’s imperial ambitions. Any conflict between Serbia and Austria-Hungary threatened to at least involve Russia, who was sympathetic to Serbian nationalism.
5. Archduke Franz Ferdinand was assassinated around 11:00 am on Sunday 28 June 1914
The Austro-Hungarian heir to the throne was murdered by Serbian nationalist Gavrilo Princip in Sarajevo. The assassination precipitated the July Crisis.
6. The first war declaration was Austria-Hungary on Serbia on 28 July 1914
The declaration caused a domino effect in the alliance system. Russia mobilised her army, which Germany considered an act of war.
7. The German war plans were called the Schleiffen Plan, and required Germany to defeat France in 6 weeks to avoid a two front war
The Schleiffen plan was fundamentally flawed: 8 of the divisions planned for use did not exist. It did fail after the German army was outmanoeuvred on The Marne.
8. 3/4s of the British parliamentary party were for “absolute non-interference at any price”
According to Prime Minister Herbert Asquith. Britain was not required by any treaty to support France or Russia in the event with war Germany. Many British politicians were against intervention.
9. Britain declared war on Germany on 4 August after Germany had invaded Belgium
Britain was obliged by the Treaty of London (1839) to protect Belgium’s sovereignty.
10. The Ottoman Empire entered the war on 1 November 1914 when Russia declared war
Russia, followed soon by France and Britain, was compelled to declare war on the Ottoman Empire when it joined the Central Powers in August, signing the Turco-German alliance.
Mobilisation and Recruitment
11. Tsar Nicholas II agreed to a full mobilisation of the Russian Army on 30 July 1914
Mobilisation was seen as a declaration of war, and Germany declared war on Russia on 1 August.
12. Russia was able to call upon the largest army on mobilisation, approximately 5 million men
Germany was second with 4,500,000 and France third with 3,781,000.
13. Britain only had an army of 733,500 men on mobilisation, but by 1918 this stood at 3,196,000
Lord Kitchener recognised that the British Army was far too small in comparison to the French and German forces and wanted to build an army of 70 divisions.
14. Lord Kitchener called for 200,000 men to sign up for the British army in the 1st month of the war – 300,000 men enlisted
War represented adventure for new recruits, who were often of the opinion that they would ‘be home by Christmas.’
15. Almost as many men joined the army voluntarily as joined after the introduction of conscription (1916) in Britain
Altogether just under 2.5 million men volunteered to fight in the British Army, approximately 25% of those eligible.
16. 750,000 British men appealed against their conscription in the first 6 months
Most were granted exemption of some sort, even if it was only temporary. Often a white feather was given to those who refused to fight out of principle alone.
17. Britain was theoretically able to call upon an Imperial population of nearly 400 million
By 1914 Britain had a vast empire and, for example, could call upon India’s population of 316,000,000.
18. By December 1915 just under 27% of Scottish men aged 15-49 had volunteered
In the end 26.4% of all Scots who enlisted became casualties.
19. Several Russian Women’s ‘Battalions of Death’ were raised by the Russian Provisional Government in 1917
Although rarely seeing conflict, these units were effective in shaming their male counterparts into fighting harder.
20. In total during the war, 13.4 million German men were mobilised
This was the highest number of men mobilised by any nation.
See also Western Front Timeline.
21. The Battle of the Frontiers (August-September 1914) was a series of 5 bloody battles in Lorraine, the Ardennes and southern Belgium
These early exchanges saw the French Plan XVII and German Schlieffen Plan collide. The offensive was a spectacular failure for the French army, with over 300,000 casualties.
22. The Battle of Tannenburg (August 1914) saw the Russian 2nd Army routed by the German 8th, a defeat from which they never truly recovered
Russian casualties at Tannenburg are estimated at 170,000 to Germany’s 13,873.
23. The Battle of Marne (September 1914) initiated trench warfare
The Battle of Marne brought an end to the first mobile phase of the war. After a communication breakdown, Helmuth von Moltke the Younger’s army dug in at the River Aisne.
24. At the Masurian Lakes (September 1914) Russian casualties numbered 125,000 to Germanys 40,000
In a second catastrophically heavy defeat Russian forces were outnumbered 3:1 and routed as they attempted a retreat.
25. The Battle of Verdun (February-December 1916) was the longest battle of the war, lasting over 300 days
26. Verdun put such strain on French forces that the British were pushed to launch the Somme Offensive
A French infantryman described the German artillery bombardment – “Men were squashed. Cut in two or divided top to bottom. Blown into showers, bellies turned inside out.”
27. The Gallipoli campaign (April 1915 – January 1916) was a costly failure for the Allies, who lost around 27,000 French and 115,000 British and dominion troops
The landing at ANZAC Cove is infamous for the appalling conditions in which approximately 3,000 ANZAC soldiers became casualties.
28. The First Battle of the Somme (1916) was one of the bloodiest battle’s of the war, with Britain losing 460,000 men, the French 200,000 and Germans nearly 500,000
Britain lost around 60,000 men on the first day alone.
29. The Spring Offensive (March – July 1918) saw German stormtroopers make huge advances into France
Having defeated Russia, Germany moved vast numbers of troops to the Western Front. However, the offensive was undermined by supply issues – they could not keep up with the rate of advance.
30. The Hundred Days Offensive (August-November 1918) was a rapid series of Allied victories
Beginning at the Battle of Amiens the German forces were gradually expelled from France and then back past the Hindenburg line. Widespread German surrender led to armistice in November.
31. At the start of the war, soldiers on all sides were issued with soft hats rather than steel helmets
Soldier’s uniforms and equipment in 1914 did not match the demands of modern warfare. Later in the war, soldiers were issued with steel helmets to protect against artillery fire.
32. A single machine gun could fire up to 600 rounds a minute
At ‘known range’ the rate of fire of a single machine gun was estimated much as 150-200 rifles. Their awesome defensive capability was a major cause of trench warfare. See also 6 Important Machine Guns.
33. Germany was the first to use flamethrowers – at Malancourt on February 26, 1915
Flamethrowers could fire jets of flame as far as 130 feet (40 m).
34. In 1914-15 German statistics estimated that 49 casualties were caused by artillery to every 22 by infantry, by 1916-18 this was at 85 by artillery for every 6 by infantry
Artillery proved the number one threat to infantry and tanks alike. Also, the post-war psychological impact of artillery fire was massive.
35. Tanks first appeared on the battlefield at The Somme on 15 September 1916
Tanks were originally called ‘landships.’ The name tank was used to disguise the production process from enemy suspicion. See also 5 Important Tanks.
36. In 1917, explosives blowing up beneath the German lines on Messines Ridge at Ypres could be heard in London 140 miles away
Building mines through No Man’s Land to plant explosives under enemy lines was a tactic used before a number of major assaults.
37. An estimated 1,200,000 soldiers on both sides were victims of gas attacks
Throughout the war the Germans used 68,000 tons of gas, the British and French 51,000. Only around 3% of victims died, but gas had the horrific ability to maim victims.
38. Around 70 types of plane were used in by all sides
Their roles were largely in reconnaissance to begin with, progressing to fighters and bombers as the war progressed. See also 12 Important Aircraft.
39. On 8 August 1918 at Amiens 72 Whippet tanks helped make an advance of 7 miles in one day
General Ludendorff called it “the black day of the German Army.”
40. The term “dogfight” originated during WWI
The pilot had to turn off the plane’s engine occasionally so it would not stall when the plane turned sharply in the air. When a pilot restarted his engine midair, it sounded like dogs barking.
The War at Sea
41. The Battle of Heligoland Bight (August 1914) was the first naval battle of WW1, and a victory for Britain
The British fleet ambushed and sunk three German light cruisers and one destroyer.
42. In 1914 SM U-9 (a German U-boat) sank 3 British armed cruisers in under an hour
43. On 7 May 1915 the cruise ship Lusitania was torpedoed by a German U-boat – 1,198 people were killed, including 128 Americans
The wrecklessness of German submarine warfare was an influence on the United States decision to join the Allies in 1917.
44. Between October 1916 and January 1917 1,400,000 tons of Allied shipping was lost to German U-boats
45. Germany built 360 U-boats, 176 of which were lost
46. 50% of all British merchant shipping was sunk by German U-boats
47. The Battle of Jutland (31 May – 1 June 1916) was the largest sea battle of the war – Britain lost more battleships and more than twice as many sailors than Germany
In the largest full-frontal naval battle of the war 14 British ships were lost to Germany’s 11. However, it was not the knock-out blow that the Germans required.
48. The North Sea was heavily mined by both sides
Under a 1907 treaty opponents could only mine 3 miles off an enemy’s coastline but both sides ignored this rule.
49. Such was the success of German U-boat attacks that the British planned to direct attack at Passchendaele toward German submarine bases
The attack failed, with Britain suffering massive casualties.
50. The Allied naval blockade of Germany (August 1914 – January 1919) caused immense hardship for the German population
Germany was heavily reliant on imports. An academic study in 1928 put the death toll caused by the blockade at 424,000 lives.
51. In December 1914 the German Navy bombarded Scarborough, Hartlepool and Whitby, killing 18 civilians
As this poster suggests, the incident created outrage in Britain and was used for later propaganda.
52. Over the course of the war, 700,000 women took up posts in the munitions industry
With many men going to the front, there was a labour shortage – many women filled vacant positions.
53. In 1917 anti–German sentiment forced George V to change the Royal Family’s name from Saxe–Coburg and Gotha to Windsor
Many road names in Britain were changed too.
53. There were 16,000 British conscientious objectors who refused to fight
Some were given non-combatant roles, others were imprisoned.
54. In Britain there were toy tanks available just six months after their first deployment
56. The female mortality rate rose in Germany from 14.3 in 1,000 in 1913 to 21.6 in 1,000, a bigger rise than England, due to hunger
It is likely that hundreds of thousands of civilians died from malnutrition — usually from typhus or a disease their weakened body could not resist. (Starvation itself rarely caused death).
57. In both Britain and France women accounted for around 36/7% of the industrial workforce by the end of the war
58. The winter of 1916-1917 was known as the “Turnip Winter” in Germany
Because that vegetable, usually fed to livestock, was used by people as a substitute for potatoes and meat, which were increasingly scarce
59. By late 1916 the German meat ration was only 31% of peacetime, and it fell to 12% in late 1918
The food supply increasingly focused on potatoes and bread – it became harder and harder to buy meat.
60. When soldiers returned there was a baby boom in Britain. Births increased by 45% between 1918 and 1920
61. Australian Private Billy Sing sniped at least 150 Turkish soldiers at Gallipoli
His nickname was ‘Murderer’.
62. US Sergeant Alvin York was one of the most decorated American soldiers – in the Meuse Argonne Offensive (1918) he led an attack on a machine gun nest which killed 28 enemy and captured 132
He was later awarded the Medal of Honor.
63. During a patrol over Italy in March 1918, Lt Alan Jerrard’s Sopwith Camel was hit 163 times – he won the VC
64. The youngest recipient of the Victoria Cross, Boy (First Class) John Cornwell, was 16 years old
He stayed at his post for over an hour despite receiving a fatal wound.
65. 634 Victoria Crosses were awarded during WW1
166 of those were awarded posthumously.
66. The Red Baron of Germany was the war’s greatest flying ace
Baron Manfred von Richthofen was credited with 80 kills.
67. Edith Cavell was a British nurse who helped 200 Allied soldiers escape from German-occupied Belgium
The Germans arrested her and she was executed by a German firing squad. Her death helped turn global opinion against Germany.
68. Anibal Milhais, the most decorated Portuguese soldier of the war, successfully and single-handedly withstood two German assaults
His resistance and rate of fire during a German ambush convinced the enemy that they were up against a fortified unit rather than a lone soldier.
69. Renegade Pilot Frank Luke, the ‘balloon buster’, claimed 18 victories in total
On September 29 1918 he downed 3 balloons but was fatally injured in the process.
70. Ernst Udet was Germany’s second greatest flying Ace, claiming 61 victories
Udet would enjoy a playboy lifestyle after the war. However he re-enlisted in World War Two and committed suicide in 1941 during Operation Barbarossa.
Animals in War
71. A pigeon named ‘Cher Ami’ was awarded the Croix de Guerre avec Palme for her assistance in saving 194 American soldiers trapped behind German lines in 1918
She made it back to her loft despite having been shot through the breast, blinded in one eye, covered in blood and with a leg hanging only by a tendon.
72. With so many horses were enlisted, Lizzie the elephant was used to cart munitions in Sheffield
73. Sergeant Stubby, a Boston Bull Terrier, was the most decorated dog of the war and the only one to become sergeant
Stubby was very useful for detecting incoming shell fire, hearing it before humans could.
74. On the first day of the Battle of Verdun 7,000 horses were killed by shelling
75. Roughly 1 million dogs died in WW1
76. Roles for dogs included: sniffing out enemies, carrying supplies, finding the wounded, delivering messages and companionship
77. In Britain killing, wounding or molesting a homing pigeon was punishable with 6 months imprisonment
This came into force after the Defence of the Realm Act (1916).
78. Approximately 8 million horses on all sides died
79. Peter the Cat served at the front with the Northumberland Hussars from 1914 to 18
Cat and dogs often served as mascots for frontline troops.
80. By the end of the war, 800,000 horses and mules were in service in the British army
Image from Who were the real warhorses of World War One? – BBC iWonder. The number of horses involved in the war effort created a headache for the British Treasury once victory arrived.
This section makes grim reading and viewing – but the war was extremely grim. See also Which Countries Lost the Most?
81. Total casualties caused directly by the war are estimated at 37.5 million
81. Approximately 7 million combatants were maimed for life
82. Germany lost the most men, with 2,037,000 killed and missing in total
83. On average 230 soldiers perished for every hour of fighting
84. 979,498 British and Empire soldiers died
86. 80,000 British soldiers suffered shell shock (roughly 2% of all that were called up)
Shell shock was an incapacitating mental illness believed to be brought on by intense sustained artillery shelling.
85. 57.6% of all combatants became casualties
86. It cost the Allies $36,485.48 to kill an opposing serviceman – significantly more than it cost the Central Powers
Niall Ferguson makes these estimations in The Pity of War. See also The Human and Monetary Costs of World War One in 7 Graphs.
88. At nearly 65% the Australian casualty rate, proportionate to total embarkations, was the highest of the war
89. 11% of France’s entire population was killed or wounded
90. On the Western Front total casualties were 3,528,610 dead and 7,745,920 wounded
The Allies lost 2,032,410 dead and 5,156,920 wounded, The Central Powers 1,496,200 dead and 2,589,000 wounded.
91. The armistice on the Western Front was signed on 11/11/1918 at 11 AM
The armistice was signed in a train carriage in Compiègne. When Germany defeated France on 22 June 1940, Adolf Hitler insisted that the armistice was signed in exactly the same carriage.
92. 4 empires collapsed at the end of the war: The Ottoman, Austro-Hungarian, German, and Russian
93. Finland, Estonia, Latvia, Lithuania, and Poland emerged as independent nations
94. The collapse of the Ottoman Empire led to Britain and France taking their colonies in the Middle East as League of Nations mandates
Britain took control of Palestine and Mesopotamia (later Iraq) and France took control of Syria, Jordan and Lebanon.
95. Russia underwent two revolutions – in October 1917 Vladimir Lenin’s Bolshevik Party took control
The first revolution in March had led to the creation of a Provisional Government, but their failure to stop the war brought massive support for the Bolsheviks.
95. Under the terms of the Treaty of Versailles, Germany was forced to accept guilt for the war and pay $31.4 billion in reparations
That is approximately $442 billion in today’s money.
96. Germany’s army was capped at 100,000 and its navy at 6 battleships, no air-force was allowed
Germany’s peace time strength was 761,00 prior to the war, so this was a significant reduction.
97. Germany lost 13% of its European Territory – more than 27,000 square miles
98. Many nationalists in Germany called the signatories of the Treaty the ‘November Criminals’ and refused to accept they had lost the war
This led to the ‘stabbed in the back’ myth – some nationalists blamed those responsible for signing the Treaty of Versailles, the new Weimar Government and Jews for the defeat of Germany.
99. The League of Nations was founded on 10 January 1920 with the mission of maintaining world peace
However, without the USA, Germany or Russia joining the League, it was doomed to impotence.
100. French General Ferdinand Foch said this of the Treaty of Versailles:
And he was right! When Adolf Hitler came to power in Germany in 1933/34, he completely disregarded the treaty and used it as an excuse to fulfill expansionist policies. The failure of the signees of the Treaty of Versailles of the League of Nations to stop him led to World War Two twenty years later.
- Scott Addington, The First World War Fact Book
- Niall Ferguson, The Pity of War
- Philip J. Haythornthwite, World War One Source Book
- John Ellis & Michael Cox, The World War I Databook: The Essential Facts and Figures for all the Combatants
- Arthur Banks, A Military Atlas of the First World War