# How the First World War unfolded From a wrong turn in Sarajevo to the hall of mirrors at Versailles: how one assassination consumed a continent. *This story led to: How the Second World War unfolded* *This story part of: Military and security* *The Ottoman Empire part of this story* > A wrong turn by a driver put the Archduke in front of a nineteen-year-old with a pistol. Within five weeks, every great power in Europe was at war. ## 28 June 1914 — Assassination of Archduke Franz Ferdinand Gavrilo Princip shoots the heir to the Austro-Hungarian throne and his wife Sophie during a state visit. > The alliance system now worked like a trap: Russia mobilized to protect Serbia, which pulled in Germany, which pulled in France. ## 28 July 1914 — Austria-Hungary declares war on Serbia After Serbia accepts most but not all of the July Ultimatum, Austria-Hungary declares war, one month to the day after the assassination. > Germany’s war plan required beating France quickly before Russia could fully mobilize, and the fastest road to Paris ran through neutral Belgium. ## 1 August 1914 — Germany declares war on Russia Germany answers Russian mobilization with a declaration of war, activating the long-planned two-front strategy. > The quick victory never came. The German advance was stopped within sight of Paris. ## 4 August 1914 — Germany invades Belgium; Britain enters the war German armies cross into neutral Belgium; Britain, guarantor of Belgian neutrality, declares war on Germany the same day. > With the western front frozen, both sides looked for a way around, and found only new places to bleed. ## 5 September 1914 to 12 September 1914 — First Battle of the Marne French and British forces halt the German advance on Paris; both sides dig in, beginning four years of trench warfare. > 1916 became the year of the great attrition battles, fought over yards of ground. ## 19 February 1915 to 9 January 1916 — Gallipoli campaign An Allied attempt to knock the Ottoman Empire out of the war by forcing the Dardanelles fails at great cost. > To relieve pressure on Verdun, the British launched their own offensive on the Somme. ## 21 February 1916 to 18 December 1916 — Battle of Verdun The longest battle of the war; France holds Verdun at a combined cost of some 700,000 casualties. > The next year the war became truly global, and one of its original members collapsed. ## 1 July 1916 to 18 November 1916 — Battle of the Somme The British Army suffers 57,000 casualties on the first day alone; five months of fighting gain roughly six miles. > While fresh American strength gathered, Russia buckled. ## 6 April 1917 — United States enters the war Unrestricted submarine warfare and the Zimmermann telegram bring the United States into the war on the Allied side. > The new Bolshevik government made peace at any price. ## 7 November 1917 — October Revolution The Bolsheviks seize power in Russia on a promise of peace, land, and bread. > Freed in the east, Germany gambled everything on one last offensive in the west before the Americans arrived in force. ## 3 March 1918 — Treaty of Brest-Litovsk Soviet Russia leaves the war, ceding vast territories to Germany. > The gamble failed. The Allied counteroffensive rolled forward through the autumn until Germany asked for terms. ## 21 March 1918 to 18 July 1918 — German spring offensive Germany's final offensives gain more ground than any since 1914 but exhaust her last reserves. > The peace that followed was written by the victors, and it planted the resentments the next war would grow from. ## 11 November 1918 — Armistice of 11 November 1918 Fighting ends at the eleventh hour of the eleventh day of the eleventh month; some nine million soldiers are dead. ## 28 June 1919 — Treaty of Versailles The peace treaty assigns Germany responsibility for the war, imposes reparations, and redraws the map of Europe. Signed five years to the day after the assassination.