100 years since end of WWI: 70 million soldiers fought a Great War that left more than 15 million dead

World War I or the Great War, was a global war that originated in Europe and later engulfed major countries around the world. The "war of all wars" was fought for more than four years between 28 July 1914 to 11 November 1918, and mobilised more than 70 million military personnel across the world. Triggered by the assassination of the Archduke, Franz Ferdinand and his wife by Bosnian revolutionary, Gavrilo Princip, the war not only reformed the global balance of power but also left behind rivers of blood, killing more than 15 million people and injuring another 21 million. A hundred years have passed since WWI, but the scars left behind by the blood and gore still haunts the human race. Here is a look back at the first World War: (Image: Reuters)

Pictured: American soldiers react to a gas attack, likely used for training purposes. (Image: Reuters)

Pictured: An American troupe from Regimental Headquarters Company, 23rd Infantry, shoots a 37mm gun, advancing against German entrenched positions. (Image: Reuters)

Pictured: A doctor from the American Expeditionary Force tends to an injured soldier. (Image: Reuters)

Pictured: From left to right- American, British, French, and German gas masks are seen in the picture from World War I. (Image: Reuters)

Pictured: Two American soldiers, James H. White and Corporal Howard Thompson, who were part of a group that killed and captured several Germans in no man's land. Thompson holds a pistol taken from a German soldier killed by White. (Image: Reuters)

Pictured: The first World War pioneered many inventions in technology and science. Chief among them were tanks, which were invented to break the trench warfare stalemate. (Image: Reuters)

Pictured: Canadian soldiers carrying war trophies, return victorious from Courcelette during the Battle of the Somme in 1916. (Image: Reuters)

Pictured: The erstwhile US president Woodrow Wilson in Europe for the Paris peace conference. (Image: Reuters)

Pictured: US Marines in France. (Image: Reuters)

Pictured: People gathered at Times Square, holding copies of newspapers with a headline about the signing of the Armistice to end the war. (Image: Reuters)