The total number of military and civilian casualties in World War I was more than 37 million. There were over 16 million deaths and 20 million wounded.
Here are the top 10 deadliest battles of WWI.
10. Battle of Tannenberg
182,000 total casualties
Russian soldiers in winter uniform. Photo / Getty
This battle between Russia's Second Army against Germany's Eighth Army took place from 26-30 August, 1914.
Despite being outnumbered by two Russian field armies, the Germans managed to inflict a huge defeat on the Russians at Tannenberg, decimating the second army, and annihilating the majority of the first army.
The German's ability to rapidly deploy their troops by train, was remarkable. The Russians suffered 170,000 casualties to the Germans 12,000.
9. Battle of Arras
278,000 total casualties
The Labyrinth, Arras, France. The British Army dug a huge system of tunnels beneath the German lines at Arras in preparation for an assault launched in April 1917. Photo / Getty
By 1917, the Western Front had been at a stalemate for two years. Both sides had already incurred millions of casualties, thanks in large part to battles at Verdun and the Somme. The Allied high command needed to break the German lines, so formed a plan to assault the trenches at the town of Arras. These were a maze of trenches stretching from the Belgian coast to the Swiss border.
This battle was tactically a British victory, but didn't result in the breakthrough the Allies had hoped for. The Allies lost 158,000 casualties in the assault, to a German loss of 120,000. This battle was considered indecisive.
8. The Gallipoli Campaign
473,000 total casualties
A salute to the fallen on the 99th anniversary of Gallipoli land campaign held at the New Zealand National Memorial during ANZAC day on the Gallipoli Peninsula, Turkey. Photo /Getty
During this campaign the Australian and New Zealand soldiers began to see themselves as a separate and unique country from Britain.
By 1915 casualties had mounted and the allies decided to open up a second front. Sir Winston Churchill decided on an attack on the Dardanelles in modern-day Turkey to threaten the Ottoman capital of Constantinople.
The hope was this would help break the deadlock on the Western Front, and bring relief to the beleaguered Russians by opening up a sea route for resupply.
Initial naval attacks failed and the allies decided on an assault to crush the Ottoman army. The Turkish troops resisted and the allies became bogged down on the beaches.
The Gallipoli front eventually bogged down into the same trench warfare as seen on the Western Front as British, Australian and New Zealand forces clashed with the Turks, trying to break out of their beachheads.
The allies ended up losing 220,000 men to the Turks 253,000, and the Ottoman Empire earned a stunning victory.
7. The First Battle of the Marnes
483,000 total casualties
Fought from 5-12 September, 1914, this battle put an end to the German offensive that went on for a month. It opened up the war which had by then reached the outskirts of Paris.
Six French field armies and one British counterattacked the Germans along the Marne River and forced the German Imperial Army to relinquish their push toward Paris and retreat northeast.
Despite the Allied victory, the battle was costly; the allies suffered 263,000 casualties, and the Germans 220,000.
This battle forced the Germans to retreat and begin building fortifications, which resulted in the allies responding and the infamous trench warfare.
6. The Serbian Campaign
633,500+ total casualties
Unknown Soldier Tomb of Avala, Belgrade. Photo / Thinkstock
The Serbian Campaign began with the Austrian shelling of Belgrade on 29 July, 1914, followed by a military invasion of Austria-Hungary into Serbia on 12 August.
The Serbians took heavy losses during this campaign, their army of 420,000 was decimated to around 100,000.
The Serbians lost a total of 1,1000,000 during the war - soldiers and civilians. This represented about 27% of Serbia's overall population, about 60% of their male population.
5. The Battle of Passchendaele
848,614 total casualties estimated
Also known as the Third Battle of Ypres, the aim of the battle was to breakthrough at the village of Passchendaele in West Flanders, Belgium and beat back the Germans.
Soldiers fought under miserable conditions, and both sides suffered major casualties. The battle only allowed the British to acquire small territorial gains for their efforts.
Mud was a constant feature of the landscape, bogging down tanks and even drowning men. The allies lost a total of 448,614 men to the Germans 400,000.
4. The Battle of Verdun
976,000 total casualties
This battle was fought between the German and French armies between 21 February, 1916 to 18 December, 1916.
The French managed to recapture most of the ground they lost to the Germans, including Fort Douaumont, but lost some 542,000 casualties, while the Germans lost some 435,000.
Nearly 40 million artillery shells were exchanged during the battle, marking the area with craters which are still visible to this day.
Verdun was to the French and Germans what the Somme was to the British; a symbol of the horrors of war, and of the futility of World War I.
3. Battle of the Somme
1,219,201 total casualties
The Battle Of The Somme. Photo / Getty
This battle took place between 1 July to 18 November, 1916. Battles took place on both sides of the Somme River in France. The Somme is remembered as an example of the senseless slaughters of the war.
The battle was an Allied victory, but they paid a heavy price of 623,906 casualties, including 100 tanks and 782 aircraft. The Germans lost nearly 600,000 men.
The British prepared for the offensive with a massive several day artillery barrage on the German lines. On the opening day of the battle, the British suffered 60,000 casualties including the death of 19,240 in one day. It was the greatest single day loss of life in the history of the British Army. The battle was strategically important to the allies, as it forced the Germans to withdraw 40 miles and later set the stage for the final victory in 1918.
2. The Spring Offensive
1,539,715 total casualties
This battle began on 21 March, 1918. During this offensive, deep advances by both sides took place.
The allies managed to halt the advance of the Germans who lost more than 680,000 because of their push toward ending the war. Most German losses were to the storm trooper units.
The allies lost more than 850,000. The Battle of Belleau Wood which occurred during this offensive became one of the most famous battles in American history. It was where the US Marines engaged the Germans and stopped them cold.
1. Hundred Days Offensive
1,855,369 total casualties
This series of offensives occurred during the final period of WWI. It began on 8 August and went until November, 1918.
The result of this offense was a resounding success for the allies which broke the German Army.
The Germans sustained heavy casualties, 785.733, but the allies paid dearly losing a total of 1,069,636 casualties, including 127,000 Americans.
The loss and collapse of the German Empire resulted in humiliating and demanding terms in the peace treaty.
