A red cross nurse writing down last words of mortally wounded soldier, taken around 1917.

Oldest Austrian soldier of WW1, a 79-year-old Gaspar Wallnöfer, veteran of Habsburg campaigns in Italy in 1848 and 1866, September 1917

Australian soldiers of the 4th Division field artillery brigade on duckboard track in Château Wood, near Hooge, Ypres salient, 29 October 1917. Photo by Frank Hurley

Infantrymen of the 1st Australian division during a rest, taken at Ypres, Belgium, 1917. (colorized by me)

The last known photograph of Tsar Nicholas II, seen with his wife Alexandra, c. August 1917

Russian and Austro-Hungarian officers during the ceasefire on the Eastern Front, 1917.

Austro-Hungarian troops executing captured rebellious Serbians and other Slavs during the occupation of Serbia in WWI by the Central Powers, 1917. Serbia lost 850,000 people, which was almost a quarter of its population at that time.

British Mark IV Female Tank With Lewis Guns, 1917

Morning a Passchendaele (1917)

French children playing frontline soldiers with full equipment and their own trench, 1917.

Loggers hold a cross-cut saw across a giant Sequoia tree’s trunk in California. 1917.

Woman picketing the White House, 1917

Austro-Hungarian soldiers pose with their homemade trench maces atop a mountain on the Italian Front, c. 1917

Australian field artillery soldiers move through what's left of Château Wood during the Third Battle of Ypres - 1917

A smiling Alexei Nikolaevich Romanov and his teacher in captivity in Tobolsk, Siberia about one year before his death - ca. 1917

A little French paper boy selling papers in the Canadian line. June, 1917.

A Tsarist Russian and Austro-Hungarian officer posing together during ceasefire on Eastern front, December 1917

Swedish Troops Armed with Husqvarna Pistols, 1917 (Colorized)

Civil War veteran Captain Edward Camden. When the United States joined the First World War, he put on his old uniform and attempted to enlist. He was 81 years old. 1917

A German officer and an NCO wearing portable sound locating apparatus's to detect enemy aircraft. Western Front, 1917.

Anastasia and Maria Romanov making faces at their camera, 1917

Aftermath of the Halifax Explosion, which took place December 6, 1917

The stern of Ise-class battleship Hyūga during her construction, 1917.

Possibly in a position located in the Vosges mountain range in eastern France, gasmask-wearing infantrymen cram together for a memento photograph. July, 1917.

A Sami woman, toddler, and infant in Lapland, Finland, 1917

Serbian and French colonial soldiers on Macedonian front, 1917.

Electric Charging, 11th July 1917.

Unknown member of the Russian aristocracy selling newspapers on the streets of Paris to scrape a living following the revolution of 1917. .

Austro-Hungarian stormtroopers practicing trench raiding, polygon in Levico (now Italy), 1917

Liliʻuokalani, the overthrown final monarch of the Hawaiian Kingdom, sitting on the porch of her private residence with her dog Poni, 1917

Bathing girls at Paragon Park, Nantasket Beach, 1917 (Colourized)

Sergeant Stubby, the most decorated dog in U.S. Military History. Beginning in 1917, he spent over 18 months on patrol in WWI, participated in 17 battles, and saved the lives of countless men on the battlefield.

Austrian officers playing music into radio transmitters that broadcast it to soldiers in nearby trenches, WW1, 1917

German soldier lighting his cigarette with a flamethrower, 1917.

The morning after the first battle of Passchendaele, 12 October 1917.

British Army fatigue party carrying duckboards over a support line trench at night. Cambrai, 12 January 1917. (Colourized)

A young Harry S. Truman posed in uniform during the First World War in 1917.

Manfred von Richthofen (1892-1918), better known as the Red Baron, wears his friends clothing to not be recognized in public (Schweidnitz, 1917)

Picture of the smoke cloud approx 20 seconds after the explosion that rocked Halifax on December 6th, 1917.

Daughters of Emperor Nicholas II of Imperial Russia: in the garden of the Alexander Royal Palace - the grand duchesses had their heads shaved due to measles. From L to R: Russian Duchesses, Anastasia Nikolaevna, Tatiana, Olga, and Maria Nikolaevna: in the spring of 1917.

A German officer and an NCO wearing portable sound locating apparatus's to detect enemy aircraft (this was a type of early radar). Western Front, 1917.

German pilot Adolf Auer in his plane in 1917, although he wasn't Jewish he painted the star of David symbol on his plane after future Nazi party member Hermann Goring made anti semitic remarks about his co pilot.

Russia, 4 July 1917: Street protestors on Nevsky Prospekt, Petrograd (now St Petersburg) fleeing moments after soldiers of the Provisional Government opened fire with machine guns.

Four German soldiers in bunk beds who had been woken up for a surprise photograph during World War 1, c. 1917.

German soldier celebrating easter and holding snow easter egg, Eastern front, c. 1917.

Corporal Benito Mussolini in a trench on the Carso, 1917

Corporal Fred McIntyre, known as Devil's Man, just returned with the Harlem Hellfighters. With him is the photograph of the Kaiser that he carried around for luck. 1917 or '18

On this day in 1917 began the February Revolution to overthrow Tsar Nicholas II in Russia

Indochinese soldiers stationed in Korçë, Albania while serving with the French army during the First World War, 1917

T.E. Lawrence, or "Lawrence of Arabia" with camel and Enfield rifle, c. 1917