Winston Churchill, then Lord of the Admiralty, next to a plane in 1914.
Archduke Franz Ferdinand exiting a train in Sarajevo, on June 27, 1914, the day before his assassination. His assassination by a Bosnian-Serb nationalist is widely considered to have sparked World War I.
Unlocated file picture taken during the first World War of people gathering horses requisitioned to go to the front.
A file picture taken in the year 1916 shows French soldiers unloading trucks near Verdun battlefield, eastern France during WWI. The Western Front battle cost the lives of 163,000 Frenchmen.
A picture taken by an ex-serviceman in 1916 shows a horse-drawn carriage passing through the ruined French city of Verdun, during World War I.
Picture dated 1916 of the ruined city of Verdun, France, during World War I, taken by an ex-serviceman.
An undated picture shows (L to R) French President Raymond Poincare, King Albert I of Belgium, French War Minister Alexandre Millerand, Commander-in-Chief of the French Armies Joseph Joffre and Commander of Allied Forces Ferdinand Foch reviewing the troops during World War I.
A picture taken in 1918 shows French General Philippe Petain (C) attending a meeting at Allied Armies General Headquarters. During WWI Petain became a national hero for his defence of the town of Verdun along the Western Front.
Unknown soldiers pose with their military decorations during World War I.
News that the German light cruiser the Emden has been destroyed by HMS Sydney of the Australian Navy is posted in the Main Hall at the Baltic Exchange in London, 9th November 1914.
French soldiers moving into attack from their trench during the Verdun battle on the Western Front in France, during the first World War.
A photo taken during the Russian civil war in Tsaritsyn (Volgograd and Stalingrad) of the armoured train of the Second Siberian Red Army.
An undated picture shows French Commander in Chief of Allied Armies Ferdinand Foch (2nd R), General Joseph Joffre (R), Commander-in-Chief of the French Armies, and US General John Pershing (2nd L), Commander-in-chief of the American Expeditionary Force, inspecting marching troops during World War I.
A picture taken in September 1914, during World War I, shows French General Joseph Joffre (2nd R), Commander- in-Chief of the French Armies, and General Michel Joseph Maunoury (R) on the front during the First Battle of the Marne between September 5 and September 12, 1914.
A picture taken on June 3, 1922 shows (L to R) Marshal of France Joseph Joffre and Marshal of France Philippe Petain reviewing the troops during the inauguration in Metz, eastern France.
An undated picture shows (L to R) Commander-in-Chief of the French Armies Marshal Joseph Joffre and Commander of Allied Forces Marshal Ferdinand Foch during World War I.
King Peter I of Serbia (L, on oxcart) and Serbian troops in November 1915, following the invasion of Serbia by the joint forces of Germany, Austro-Hungary and Bulgaria in October 1915.
Unlocated photo of people carrying their belongings in a town near the front, during the World War I.
Undated picture showing French artillery officer Alfred Dreyfus (L) during WWI. Dreyfus had previously been convicted of treason.
Picture taken during the first World War of Head of French government Georges Clemenceau visiting a trench.
Picture taken during WWI of the head of the French government Georges Clémenceau (R), during lunch with soldiers on the front. Second (R) is his son general Michel Clémenceau.
An undated picture of Queen of the Belgians Elisabeth of Bavaria (C) and the Belgian Royal family at her return to Belgium after World War I.
A picture taken on October 16, 1925 shows French Foreign Minister Aristide Briand and his German counterpart Gustav Stresemann during the signing ceremony of the Locarno Treaties. It enabled Germany to be admitted to the League of Nations.
A picture taken on June 21, 1930 shows (L to R) French War Minister Andre Maginot, Marshal Joseph Joffre and Marshal Philippe Petain at the inauguration of Joffre's monument in Chantilly, northern France.