World War I

World War I, also known as the 1914-18 War (TV: The War Games) was a major conflict on Earth fought over four years from 1914 to 1918. (TV: The War Games) It was referred to as "the War to End All Wars", (TV: To the Last Man, PROSE: The Way Through the Woods) or "the War to End Wars". (TV: The War Games)

Foreseeing
In 1903, after receiving a wealth of information from the future, Grigori Rasputin foresaw the Great War. (AUDIO: The Wanderer) The time travelling Family of Blood, while in 1913, warned some people there would be a war the next year. (TV: The Family of Blood)

Origin
It was caused in part by the influence of the Nemesis statue passing by Earth in 1913. (TV: Silver Nemesis) However, the ostensible reason was that a Serbian nationalist Gavrilo Princip assassinated the Austrian Archduke Franz Ferdinand in Sarajevo in June 1914. Austria issued a list of demands to Serbia, which were rejected. In response, Austria prepared to invade Serbia. Russia was allied to Serbia and started mobilising its troops. Knowing that France was also allied to Serbia, Germany, which was itself allied to Austria, decided to attack France first because France wanted the provinces of Alsace-Lorraine back. In order to do that, Germans had to march through Luxembourg and Belgium. However, the United Kingdom had a treaty to protect Belgium. Thus, most of the major powers were pulled into the war, and the others soon chose a side too. (PROSE: Human Nature)

At one point, the Eleventh Doctor grew fearful as he began to suspect that the Daleks had conditioned Princip to commit the assassination so humanity would be plunged into war, allowing the Daleks to make advancements with the Dalek Project. Yet the Doctor ultimately never found any conclusive evidence to confirm his suspicions and conceded that it was only a possibility. (COMIC: The Dalek Project)

The war
The United Kingdom did not engage in combat until the end of August 1914. (COMIC: The Weeping Angels of Mons)

Some of the battlegrounds were Mons (COMIC: The Weeping Angels of Mons), Passchendaele, the Somme, Verdun, Tannenberg and Ypres. (TV: To the Last Man, AUDIO: The Next Life, PROSE: Byzantium!, Remembrance of the Daleks, Illegal Alien) A million British soldiers died during the war. (TV: To the Last Man)

On Christmas Day 1914, a festive truce was called and soldiers on both sides participated in football matches in no-man's land. (PROSE: This Town Will Never Let Us Go) They also conversed and shared cigarettes. (PROSE: The Little Drummer Boy, COMIC: The Forgotten) The celebrations were witnessed by the First Doctor, Steven Taylor, and Sara Kingdom; (PROSE: The Little Drummer Boy) the Fifth Doctor and Peri Brown; (PROSE: Never Seen Cairo) and the Ninth Doctor and Rose Tyler. (COMIC: The Forgotten) The next day, soldiers resumed fighting. (PROSE: The Little Drummer Boy)

On 7 May 1915, the RMS Lusitania was torpedoed by the German U-boat and sank, precipitating the entry of the United States of America into the war two years later. (AUDIO: The Sirens of Time)

In 1915, Wilfred Hollins was killed in the war. (AUDIO: Nightshade)

In 1917, George Newman fought on the Italian front. (AUDIO: Fiesta of the Damned)

The immortal Jack Harkness fought in the war in the British Army, (TV: Utopia, COMIC: The Forgotten) as did Tim Latimer, Hutchinson (TV: The Family of Blood) and Major Burton. (TV: Delta and the Bannermen) Tommy Brockless also served, and was eventually executed in 1918 when, suffering from shell shock, he refused to return to the front lines. (TV: To the Last Man) Solomon and the older members of his Hooverville fought in the American army during the war (TV: Evolution of the Daleks) as did Diagoras. (TV: Daleks in Manhattan) By 1917, most young men in England had been drafted. (PROSE: The Way Through the Woods) The android Edwin Bracewell had memories of the War implanted in his positronic brain. The Eleventh Doctor speculated that these were someone else's memories. (TV: Victory of the Daleks)

The Forge ran at least two experiments for the war effort: trying to create vampire soldiers in 1915 (AUDIO: Project: Twilight) and trying to brainwash soldiers into being more aggressive in 1917. (AUDIO: No Man's Land)

A number of British and German soldiers were kidnapped by the War Lords for their War Games, fighting in a replica of the Western Front. The Second Doctor, believing the "1917 Zone" was the real conflict, called it "one of the worst wars in human history". The soldiers were eventually returned home to Earth by the Time Lords. (TV: The War Games)

11 November 1918, Armistice Day, marked the end of the war. (AUDIO: The White Room) A conference was held at Versailles in 1919 for the signing of the Treaty of Versailles. (PROSE: Illegal Alien) Under the terms of the treaty, Germany lost all of her colonies, much of her European territory and was made to accept responsibility for the war. (PROSE: Just War)

The Doctor and the war
The First Doctor, along with his granddaughter, Susan Foreman, survived a Zeppelin air raid. (TV: Planet of Giants; AUDIO: The Alchemists) The First Doctor also witnessed the Battle of Passchendaele and considered it an awful event. (PROSE: Byzantium!)

In 1914, the Third Doctor, Tobias Philby and Thomas ended up in a No Man's Land in France, where they learned of a German artillery build-up and warned the British Army of it. (COMIC: The Amateur)

The Seventh Doctor, travelling with Ace and Hex, was drawn to the Forge's experiments at Charnage Hospital in 1917 and thwarted them. (AUDIO: No Man's Land) On another occasion, he offered one private the opportunity to travel with him but the man declined. (PROSE: Front Line)

The Ninth Doctor visited at with Rose Tyler. He started the football game between the opposing troops taking part in the Christmas truce. (COMIC: The Forgotten) The Fifth Doctor also visited a battlefield during the Christmas truce, during which he met Edward Woodbourne. (PROSE: Never Seen Cairo)

The Tenth Doctor and Rose visited the war again and put a stop to the Warfreekz' observation of the battles. (COMIC: Warfreekz!)

The Tenth Doctor encountered the Weeping Angels in the town of St Michel. (COMIC: The Weeping Angels of Mons)

The Eleventh Doctor arrived at Hellcombe Hall in 1917 where, with help from Corporal Edward Anderson and Lord Hellcombe, he learned about the Dalek Project. He managed to help the Allied and German armies defeat the Daleks and their robotic drones before all witnesses to the Dalek plan could be exterminated. (COMIC: The Dalek Project)

Aftermath
In the aftermath of the war, certain women over thirty in the United Kingdom gained the right to vote. (AUDIO: The Suffering)

After the war, an influenza pandemic raged across the world. The Ice Warriors had released the virus to weaken humanity and allow them to invade. The virus killed the Ice Warriors instead. (PROSE: Cold)

The war was followed relatively quickly by World War II which began on 1 September 1939, (PROSE: Timewyrm: Exodus, AUDIO: Just War, Neverland, A Blind Eye) This war had its roots in World War I and its aftermath, with Adolf Hitler's Nazi Party defying the Treaty of Versailles in order to regain much of Germany's lost territories such as the Rhineland. (PROSE: Players, Just War)

In the aftermath, the "Kingdom of Iraq" was formed. (COMIC: A Wing and a Prayer)

Tommy Brockless, a shell-shocked WWI soldier who had been put in the care of Torchwood and preserved in hibernation for 90 years, was saddened about the Iraq War, since he had been told that this one was "The War to End All Wars." He was eventually returned to his original time period through the Cardiff Rift, completing a stable time loop that required him to survive until 2008. Unfortunately, once he returned to 1918, his memories reverted to their original state, and all his old fears of the battlefield returned. Brockless would be shot down by a British firing squad three weeks later for displaying cowardice. (TV: To the Last Man)

When Ben Jackson told him about the First World War in November 1920, Jamie McCrimmon initially assumed that it was fought against aliens. (AUDIO: The Mouthless Dead)

In 2017, some archaeologists came across the crashed Dalek saucer Survey Ship Sigma in France, one hundred years after it had crashed following the failure of the Dalek Project, and accidentally revived the surviving Daleks inside. The Eleventh Doctor arrived just in time to prevent a disaster and connected the saucer to a power line, overloading the Daleks. He saw this as him dealing with "unfinished business". (COMIC: The Dalek Project)