World War I broke out when Archduke Franz Ferdinand of the Austro-Hungarian Empire was assassinated in Sarajevo by the organization known as Black Hand. Tensions in the area had been rising for decades, though, and Europe was poised for war. The system of alliances among nations drew countries into conflicts they were not directly affected by. Essentially the world broke into two armed camps, which is how Germany, Austria-Hungary and Bulgaria found itself facing off against the world. The rise in military technology building up to the war years and arms proliferation contributed to the bloody nature of the war. By the time it ended, more than 16.5 million soldiers and civilians had perished in what would become known as the “Great War.”
There were three main groups of powers involved in the war:
Central Powers: Germany, Austria-Hungary, Turkey.
Allied Powers: Great Britain, France, Russian Empire.
Associated Powers: United States, Belgium, Bolivia, Brazil, China, Cuba, Czechoslovakia, Ecuador, Greece, Guatamala, Haiti, Hejaz, Honduras, Italy, Japan, Liberia, Nicaragua, Panama, Peru, Poland, Portugal, Romania, Serb-Croat-Slovene State, Siam, Uraguay.
Archduke Ferdinand AssassinatedJune 28, 1914
Franz Ferdinand of the Austro-Hungarian Empire and his wife, Sophie Duchess of Hohenburg, are killed by Bosnian Nationalist Gavrilo Princip. The secret Serbian organization, the Black Hand, was instrumental in the assassination, urging students to launch an assassination attempt and providing weapons to fulfill their mission.
Austria-Hungary Declares War on SerbiaJuly 28, 1914
Russia Orders Troop MobilizationJuly 29, 1914
Russia was an ally to Serbia and mobilized troops, which ensured a large conflict would occur.
Germany Declares War on RussiaAugust 1, 1914
Germany, as an ally of Austria-Hungary, declares war on Russia.
British Government Orders Naval MobilizationAugust 1, 1914
France follows suit with an order for General Mobilization.
The First Invasions BeginAugust 2-7, 1914
Germany invades Luxembourg and Belgium. France invades Alsace. British forces arrive in France to assist.
Germany Declares War on FranceAugust 3, 1914
German troops flood into Belgium as directed under the Schleiffen Plan, drafted in 1905. Belgium refuses German demands and Great Britain guarantees armed support to Belgium, issuing an ultimatum to Germany to withdraw from Belgium. Italy declares neutrality. The Grand Duke Nicholas is appointed Commander-in-Chief of the Russian armies.
British Declare War on GermanyAugust 4, 1914
This marks the official start of World War I. The US declares neutrality.
Montenegro Declares War on Austria-HungaryAugust 5, 1914
Germans begin laying mines in the open ocean.
Austria-Hungary Declares War on RussiaAugust 6, 1914
Serbia declares war on Germany.
Hostilities Commence in East AfricaAugust 8, 1914
Montenegro severs diplomatic relations with Germany.
First German Sub DestroyedAugust 9, 1914
British patrol the Channel from the air, providing protection to transports. The HMS Birmingham sinks the German submarine U-15 in the North Sea.
Britain and France Declare War on Austria-HungaryAugust 10-11, 1914
Austria-Hungary invades Russian Poland.
Austria-Hungary Declares War on BelgiumAugust 22, 1914
Japan Declares War on GermanyAugust 23, 1914
Great Britain asked for assistance from Japan because of their alliance signed in 1902. Japan accedes.
Battle of MonsAugust 23-24, 1914
Four divisions of the British Expeditionary Force encounter the German 1st Army at Mons Canal in Belgium, near the French border. This battle was part of the early days that established the Western Front between Allied and German forces.
Battle of Tannenberg BeginsAugust 26, 1914
The Russian army marches into Prussia. German forces use their superior rail system to surround the Russian army at Tannenberg. Heavy fighting delivers a crushing defeat to the Russians who lost thousands of soldiers and had 125,000 taken prisoner. Germans lost 13,000.
German Forces Burn Louvain, BelgiumAugust 26, 1914
Germans Conduct Air Raid on ParisAugust 30, 1914
Though it inflicted little damage, it terrorized civilians, which was the plan.
First Battle of MarneSeptember 5-10, 1914
Fought northeast of Paris, the First Battle of the Marne used air reconnaissance and radio intercepts to monitor German activity. It was the first time radio intercepts were used in combat. The French army, led by General Michel-Joseph Manoury, attacked the right flank of the German 1st Army, taking advantage of a hole created by the German officer, General Alexander von Kluck. Kluck had disobeyed orders to reinforce General Karl von Bulow's 2nd army and engaged the French at Marne instead. Allied troops halted the German advance.
The Great RetreatSeptember 9-14, 1914
German troops retreat to the River Aisle in what was known as the "Race to the Sea."
First Battle of AisneSeptember 12, 1914 - October 24, 1914
During the "Race to the Sea," the Allied and German troops try to outflank each other.
First Trenches Dug on Western FrontSeptember 15, 1914
Trenches would eventually run from the Northern coast of Belgium to the South of France, with a separate trench running around Ypres. They also could be found throughout France to southern Alsace in Switzerland. By the end of the war, there were approximately 25,000 miles of trenches, 12,000 of which were occupied by Allied forces.
Troops from India ArriveSeptember 14, 1914 - October 14, 1914
24,000 soldiers from India arrive in France to fight for Allies.
First Canadian Troops Arrive in BritainOctober 14, 1914
First Battle of YpresOctober 19, 1914 - November 22, 1914
Also known as the Battle of Gheluvelt. Germans capture the Belgian city of Antwerp in early October, forcing withdrawal of Allied troops to Ypres. The Germans want to control the North Sea outlets and channel ports. Combat near the Belgian city of Ypres between German, British, and French forces is reduced to attritional trench warfare.
Turkey Attacks RussiaOctober 29, 1914
Turkey enters the war by assisting Germans in a naval bombardment of Odessa, Sevastopol and Theodosia, Russia.
HMS Hermes Sunk by German Submarine in Straits of Dover.October 31, 1914
Russia and Serbia Declares War on TurkeyNovember 2, 1914
Great Britain Declares North Sea a Military ZoneNovember 3, 1914
Great Britain and France Declare War on TurkeyNovember 5, 1914
Battles of LimanowaDecember 1, 1914
Austria-Hungary battles Russia near the town of Limanowa in the Galicia Carpathian Mountains not far from Kraków. Austrian forces save their lines and prevent Russia from attacking Vienna
Pope Suggests a War Hiatus for ChristmasDecember 7, 1914
Neither side is open to creating an official cease-fire.
First German Airship Spotted in EnglandDecember 15, 1914
Unofficial Christmas Truce DeclaredDecember 24, 1914
Soldiers from opposing sides declare their own truce and put aside the war to celebrate Christmas together in the trenches. Both sides sang carols and played music. In the morning, soldiers shook hands and offered each other Christmas wishes, sharing Christmas treats and spending the day together. This kind of truce was never repeated.
Zeppelin Attack on Yarmouth, EnglandJanuary 19, 1915
Germany Declares "War Zone" Around Great BritainFebruary 4, 1915
Germany sets a submarine blockade around Great Britain, blocking merchant vessels and warships.
Battle of Masurian Lakes BeginsFebruary 7, 1915
Germany launches a surprise attack on Russian lines at Masurian Lakes during a blizzard.
Gallipoli Campaign BeginsFebruary 19, 1915
Also known as Dardannelles. British and French forces attack Turkish forces in a naval campaign to control the strait separating Europe from Asia. The Allied failure to win this campaign resulted in heavy casualties and was a blow to their position as leaders in the war.
Second Battle of YpresApril 2, 1915
Germans use poison gas for the first time. They fire more than 150 tons of lethal chlorine gas against two French colonial divisions, then launch a second gas attack on Canadian troops. Though tear gas and other uses of small amounts of gas had appeared in previous wars, this was the first distribution of chemical warfare. The battle began with bombardment and ended with poison gas.
Allied Forces Land on Gallipoli Peninsula of the Ottoman EmpireApril 25, 1915
Sinking of LusitaniaMay 7, 1915
The British ocean liner Lusitania is sunk by a German submarine, killing 1,200 people aboard, 128 of which are American. The US protests the German U-boat campaign.
Italy Declares War on Austria-HungaryMay 23, 1915
Battle of JutlandMay 31, 1915 - June 1, 1915
A British naval blockade trapped German forces at the port. The Germans thought they could ram their way through the blockade and break free, but Britain was ready for the maneuver and sent a small force to lure them away and into range of the larger fleet. It was one of the few naval battles of the war. Germany withdrew.
First London BlitzMay 31, 1915
German zeppelins make bombing raids against the British capital, killing hundreds. The Germans dropped 90 incendiary bombs and 30 grenades that night.
Italy Declares War on TurkeyAugust 21, 1915
Romania Enters WarAugust 27, 1915
Romania joined the war on the side of the Allies. But within a few months was occupied by Germans and Austrians.
Italy Declares War on GermanyAugust 28, 1915
Tsar Nicholas II Takes Control of Russian ArmySeptember 5, 1915
Bulgaria Declares War on SerbiaOctober 14, 1915
Great Britain Declares War on BulgariaOctober 15, 1915
JP Morgan & Co Agree to Loan Britain & France MoneyOctober 15, 1915
J. P. Morgan & Co. and other American bankers agree to loan Britain and France $500 million to purchase war supplies in the largest private loan in history.
Russia and Italy Declare War on BulgariaOctober 19, 1915
Churchill Resigns as Lord of AdmiraltyNovember 13, 1915
Blamed for the loss at Gallipoli, Churchill resigns Herbert Asquith's Wartime Cabinet. He rejoins the army as a battalion commander.
Allies Evacuate GallipoliDecember 1915
Allied forces evacuate Gallipoli with nearly 83,000 men, many from Australia and New Zealand.
Henry Ford's Peace Ship Sails to EuropeDecember 4, 1915
Henry Ford's Peace Ship filled with peace activists seek an end to the war through mediation.
Battle of VerdunFeb 21, 1916 - Dec 18, 1916
The Battle of Verdun was a siege by German General Erich von Falkenhayn who said the point was not to take territory, but to take lives and "bleed the French dry." Germany's artillery assault deployed more than 1,600 artillery pieces, firing 100,000 shells per hour. The French fought fiercely. At the end of the nine month battle, Germans had lost 430,000 men and France 540,000. The Battle of Verdun was the longest battle of the war.
Germany Declares War on PortugalMarch 9, 1916
Austria-Hungary Declares War on PortugalMarch 15, 1916
American Pilots Form the Lafayette Escadrille in FranceApril 16, 1916
The Battle of JutlandMay 31, 1916
In a major battle of the war, 250 ships and 100,000 men battle off the coast of Denmark's North Sea. It began with gunfire between German and British scouting forces. The British eventually force a German retreat and hold the North Sea, though both sides declared victory.
Battle of the Somme BeginsJuly 1, 1916
This battle was fought after a week of artillery bombardment that destroyed the land, creating mud and craters. The five-month long battle resulted in a loss of 420,000 British forces (60,000 of which occurred the first day), 200,000 French troops, and 500,000 German troops. The battle covered a 25-mile span.
Explosion in New JerseyJuly 30, 1916
German saboteurs set an explosion in New Jersey. It destroyed the Black Tom munitions depot, killing 3 and causing a $30 million loss.
Italy Declares War on Germany; Romania Declares War on Austria-HungaryAugust 27, 1916
Germany Declares War on RomaniaAugust 28, 1916
Turkey Declares War on RomaniaAugust 30, 1916
Bulgaria Declares War on RomaniaSeptember 1, 1916
Wilson Campaigns on "He Kept Us Out of the War"November 7, 1916
Woodrow Wilson's campaign slogan "He kept us out of war" helps him squeak by with a win in the presidential election of 1916
Battle of the Somme EndsNovember 18, 1916
The battle lasted four-and-a-half months near the Somme River in France. It was one of the bloodiest military battles in history. The Allies and Central Powers lost more than 1.5 million men. This marked a change in British tactics and strategies in the war.
First Aeroplane RaidNovember 28, 1916
This is the first German air raid by plane. The Germans hoped this would force the Royal Air Force to stay home to defend the homeland than attack the German Air Force. It did not.
Germany Sends Zimmerman Telegram to MexicoJanuary 19, 1917
The Zimmerman Telegram, intercepted by the British, was a coded message sent to Mexico to convince them to attack the US with the help of unlimited German submarine assistance. The Germans also offered Mexico territory in the US as incentive. This memo changed public opinion in America and brought the US into the war.
Reinforcements Sent to Italy1917
Italy had lost so many men holding the line that British and French soldiers were sent in to help.
German U-boat CampaignFebruary 1, 1917
Germany stepped up their U-boat campaign with orders to sink all Allied and neutral ships on sight. In the first month, nearly one million tons of shipping goods were sunk. Neutral countries ceased shipping goods to Britain, endangering US trade and travelers. Lloyd George ordered all provisional ships be given a convoy.
US Severs Diplomatic Relations with GermanyFebruary 3, 1917
White House Releases Zimmerman Telegram to the PressMarch 1, 1917
The White House publicly exposes Germany's attempt to draw Mexico into war against the United States.
Tsar Nicholas II AbdicatesMarch 15, 1917
Tsar Nicholas II abdicates during the Russian Revolution and is replaced by a provisional government.
US Declares War on GermanyApril 6, 1917
Emergency Loan Act PassesApril 24, 1917
The US begins the First Liberty Loan Bond Campaign to fund war efforts. This is followed by four other bond drives.
Selective Service Act PassesMay 18, 1917
This enables the US to form an army largely from conscription.
General John J. Pershing Arrives in EnglandJune 7, 1917
The newly selected commander of the American Expeditionary Forces arrives in England with his staff.
Congress Passes the Espionage ActJune 15, 1917
This act limits civil liberties during wartime.
US American Expeditionary Forces Land in FranceJune 24, 1917
The US 1st Division (approximately 14,000 soldiers) of the American Expeditionary Forces lands in France as the first American combat troops in Europe.
Greece Declares War on Austria-Hungary, Bulgaria, Germany and TurkeyJune 27, 1917
George M. Cohan Records "Over There"June 28, 1917
The song was sung through both World Wars as a war anthem and promise: "The Yanks are coming."
Arab Forces Align with the AlliesJuly 6, 1917
Arab forces align with the Allies to fight against Turkish forces, in what was known as the Arab Revolt.
Third Battle of YpresJuly 31, 1917
Also known as the Battle of Passchendaele. German forces try again to advance to the English Channel through the Western Front at Ypres. Nine British and six French divisions advanced on German forces near the Belgian village of Passchendaele. There were heavy losses, but the Allied forces were pushing the Germans back. They took 5,000 German prisoners. The two sides were caught agains the mountains with nowhere to go. Both sides sustained heavy losses. It was a costly and controversial offensive and showed the ineffectiveness of trench warfare.
China Declares War on GermanyAugust 14, 1917
US Troops Enter Frontline Trenches in FranceOctober 21, 1917
Russian RevolutionNovember 6-7, 1917
Vladimir Lenin Siezes PowerNovember 7, 1917
The Bolsheviks, led by Vladimir Lenin, overthrow the Provisional Government in Russia during the Russian Revolution.
Battle of Caporetto Ends in Italian RetreatNovember 10, 1917
German and Autrian-Hungarian forces decimate the Italian line along the Isonzo River. Italy suffers 700,000 casualties and a loss of 25 kilometers of land, putting German forces just 30 kilometers north of Venice. Anti-war protests increase in Italy.
US Declares War on Austria-HungaryDecember 7, 1917
The US declares war to prevent Italy from leaving the war.
Russia Agrees to Armistice Talks with GermanyDecember 1917
The new Russian government enters peace talks with Germany.
Wilson Issues "Fourteen Points to Peace"January 8, 1918
President Woodrow Wilson presents his "Fourteen Points of Peace" speech to a joint session of Congress. Through the US was in the war, Wilson was hoping for a way to end things peacefully. He laid out a 14-point plan to end the war and prevent another from occurring. The fourteenth point called for establishing an international organization responsible for helping keep peace among the nations. This organization was eventually established and called the League of Nations.
The Stars and Stripes Begins PublicationFebruary 8, 1917
The armed forces newspaper published one thousand first issues. Second Lieutenant Guy T. Visniskki was the first managing editor.
Russian Government Signs Brest-Litovsk TreatyMarch 3, 1917
Russia's new Bolshevik government signs the Brest-Litovsk Treaty with the Central Powers, officially leaving the war. Russia cedes roughly half of its industry, one-third of its farmland, and one-third of its population under the Treaty.
US Soldiers Report Influenza at Camp Funston, KansasMarch 4, 1917
The first US soldiers diagnosed with influenza at Camp Funston in Kansas. This was the start of the Spanish Flu, a global epidemic that will claim more lives than the war itself. Approximately 20-50 million people around the world perish from the pandemic, including 675,000 Americans.
Germany Launches Spring OffensiveMarch 21, 1918
The German spring offensives begin with a series of German attacks on the Western Front. The attacks strain Allied resources, nearly breaking them. It is the final offensive of the war.
US Senate Discovers the US Aircraft Industry Is UnderperformingMarch 26, 1918
The US Senate learns US American Expeditionary Force will only have 37 aircraft by July instead of the promised 12,000.
The "Red Baron" Shot Down and KilledApril 21, 1918
German flying ace Baron Manfred von Richthofen is shot down and dies.
France Suffers Defeat at Aisne RiverMay 27, 1918
Battle of CantignyMay 28, 1918
In the first independent American operation, US focus are victorious at Cantigny.
Battle of Chateau-ThierryJune 1-26, 1918
American forces stop the German attempt to cross the Marne River at Chateau-Thierry. It was a second US victory, but with heavy losses.
Battle of Belleau WoodJune 6, 1918
US Marines launch an attack at Belleau Wood. Pershing ordered a counteroffensive to drive the Germans out of Belleau Wood. In the following three weeks, the Marines, backed by US Army artillery, launched attacks in the woods. The Germans responded with artillery, machines guns and gas. It was an American victory, but with significant losses. In the end, there were nearly 10,000 dead, wounded or missing in action. The battle showed the US will and might on the battlefield.
Second Battle of the MarneJuly 15-17, 1918
French and US forces stop German advance on Paris.
Bolsheviks Execute Tsar Nicholas II and His FamilyJuly 16-17, 1918
US First Army OrganizedAugust 10, 1918
The US launches an independent fighting force in France capable of large-scale offensives and operations.
First US Soldiers Arrive in VladivostokAugust 16, 1918
US soldiers occupy Vladivostok, Russia's Siberian port. These forces will eventually grow to 9,000.
4,500 US Soldiers Land in Archangel, North RussiaSeptember 4, 1918
Meusse-Argonne OffensiveSeptember 26, 1918
The Allied forces advance on German positions in the Argonne Forest and along the Meuse River. They use more than 700 tanks, followed by infantry troops. Pershing took control of the operation, attempting to cut off Germany's second army. Allied forces captured more than 33,000 German prisoners and advanced six miles. The offensive lasted until the end of the war.
German Kaiser Wilhelm II Abdicates and Flees GermanyNovember 9, 1918
Germany Signs ArmisticeNovember 11, 1918
Germany signs the Armistice at Compiegne, France. Fighting ceases on the 11th hour of the 11th day of the 11th month.
British and American Forces Enter GermanyDecember 1, 1918
The Stars and Stripes War Orphans Adoption Campaign EndsDecember 16, 1918
The campaign raised 123,047 francs and placed 3,444 orphans for adoption.
Peace Conference Begins in ParisJanuary 18, 1919
First Anniversary Issue of The Stars and StripesFebruary 8, 1919
Draft of the Covenant of the League of Nations CompleteFebruary 14, 1919
The Treaty of Versailles officially ends WWIJune 28, 1919
Allied and German representatives sign the Treaty of Versailles. The US signs a treaty of guaranty and pledges to defend France in the event of an unprovoked attack by Germany.