The Armistice of Compiègne was signed at 5:10 AM on November 11, 1918, in a railway carriage in the Forest of Compiègne, France, at the headquarters of French Field Marshal Ferdinand Foch, Supreme Commander of Allied forces on the Western Front. Fighting between the major combatants ceased at 11:00 AM on November 11—the 11th hour of the 11th day of the 11th month. The decision to cease fire at that specific time was symbolically resonant, but strategically it meant that fighting continued from 5:10 AM to 11:00 AM—nearly six more hours of combat. Approximately 11,000 men were killed or wounded in those final hours of the First World War. The casualty count exceeded the total casualties of D-Day, the opening of Operation Overlord 27 years later. Men died in trenches, in shell holes, in no-man's-land—fighting a war that was already finished.

On November 12, 1918, celebrations erupted across the Allied world. In London, crowds filled the streets around Trafalgar Square and Parliament. In Paris, crowds celebrated in the Place de la Concorde and marched toward the Arc de Triomphe. In New York, ticker tape parades on Wall Street saw office workers tear up stock tickers and documents in jubilation. In the smaller towns and cities of Britain, France, and the United States, townspeople gathered in public squares to ring church bells, sing national anthems, and embrace. The war, the tremendous, terrible war that had lasted four years and three months and killed approximately 17 million people—soldiers and civilians—was over. The immediate response was relief and joy.

The political dimension of the Armistice was equally dramatic. Kaiser Wilhelm II of Germany, the German emperor and supreme military commander, had already fled Germany on November 10, two days before the Armistice was signed. He had taken refuge in the Netherlands, hoping the Dutch would not extradite him. The German government, newly formed under Prince Maximilian of Baden and then under Friedrich Ebert, a Social Democrat, was negotiating the Armistice with Foch and the Allied military high command. The German delegation, led by Matthias Erzberger, a civilian politician with military liaison support, faced the harsh terms that Foch imposed. Germany was to surrender 5,000 artillery pieces, 25,000 machine guns, 1,700 aircraft, 5,000 locomotives, 150,000 freight wagons, and five battleships. German forces were to withdraw from all occupied territory within 15 days.

On November 12, German forces began their evacuation of occupied territories in France, Belgium, Luxembourg, and Alsace-Lorraine. The retreat was orderly in some sectors, chaotic in others. Demoralized German soldiers, many having already suffered the defeats of the autumn of 1918, began the long march back toward German territory. Looting, pillage, and disorder marked the withdrawal in some areas. In other sectors, German commanders maintained discipline and prevented atrocities. The German army that emerged from the armistice was defeated but not destroyed; German military strength would remain a potential threat, though Germany would be severely constrained by the peace treaty that would eventually be negotiated at Versailles.

First prisoner exchanges and prisoner releases began on November 12. Hundreds of thousands of German prisoners held by the Allied powers began to be repatriated. Hundreds of thousands of Allied prisoners held in German camps began to return. The process was chaotic and would take months to complete. Many prisoners had been held in miserable conditions; disease, malnutrition, and abuse had killed thousands. The return of prisoners to their home countries was an emotional and humanitarian priority, but the logistics were staggering. Railway systems were destroyed in many areas; transportation capacity was limited. Not all prisoners could be returned immediately. Some would remain in camps or prisoner processing centers for months.

President Woodrow Wilson of the United States, who had emerged during the war as the leading voice of the Allied cause and who had articulated 14 points as the basis for a just peace, began the process of planning for the peace negotiations that would become the Treaty of Versailles. Wilson, British Prime Minister David Lloyd George, and French Premier Georges Clemenceau would meet in Paris to negotiate the settlement. The peace conference would not begin until January 1919; the treaty would not be signed until June 28, 1919. The gap between Armistice and treaty—seven months—would be a period of uncertainty about the future political and economic order of Europe.

November 12, 1918, also marked the continuation of a catastrophe that rivaled the war in its mortality: the Spanish flu pandemic. The influenza had emerged in the spring of 1918 and had reached pandemic proportions by the summer. A more virulent strain appeared in the fall of 1918; October 1918 had been the peak month of infections and deaths. By November 12, the pandemic had already killed an estimated 50 million people globally—far more than the 17 million killed in the war itself. The end of the war did nothing to end the pandemic. The movement of soldiers and the social disruptions of demobilization would continue to spread the virus. The flu would continue to kill into 1919, though with declining virulence. For many who had survived the trenches, the armistice brought relief but not safety; disease remained a deadly threat.

Domestically, American President Wilson faced political opposition from Republicans who controlled Congress after the 1918 midterm elections. Senator Henry Cabot Lodge, chairman of the Senate Foreign Relations Committee and a bitter rival of Wilson, had already begun outlining objections to the League of Nations—the international organization that Wilson championed as the cornerstone of a new world order. The political battles over the peace treaty would prove as consequential as the military battles of the war itself, and would ultimately result in the United States Senate refusing to ratify the Treaty of Versailles.

November 12, 1918, marked the end of the industrial, mechanized warfare that had defined the First World War. The trenches would soon be abandoned. The weapons would be stored or destroyed. The soldiers, millions of them, would be demobilized and returned to civilian life. The Europe that emerged from the Armistice would be profoundly changed: empires had fallen (Russian, Austro-Hungarian, Ottoman), new nations had emerged, and the political and social order had been fundamentally disrupted. The peace settlement would attempt to restore order and stability, but it would fail to satisfy the legitimate grievances of many parties and would plant the seeds of the Second World War, just 21 years away.