World War I, also known as the Great War, began in 1914 after the assassination of Archduke Franz Ferdinand of Austria. His murder catapulted into a war across Europe that lasted until 1918. During the conflict, Germany, Austria-Hungary, Bulgaria and the Ottoman Empire (the Central Powers) fought against Great Britain, France, Russia, Italy, Romania, Japan and the United States (the Allied Powers). Thanks to new military technologies and the horrors of trench warfare, World War I saw unprecedented levels of carnage and destruction. By the time the war was over and the Allied Powers claimed victory, more than 16 million people—soldiers and civilians alike—were dead.
Archduke Franz Ferdinand
Tensions had been brewing throughout Europe—especially in the troubled Balkan region of southeast Europe—for
years before World War I actually broke out.
A number of alliances involving European powers, the Ottoman Empire, Russia and other parties had existed for years,
but political instability in the Balkans (particularly Bosnia, Serbia and Herzegovina) threatened to destroy these agreements.
The spark that ignited World War I was struck in Sarajevo, Bosnia, where Archduke Franz Ferdinand—heir to the
Austro-Hungarian Empire—was shot to death along with his wife, Sophie, by the Serbian nationalist Gavrilo Princip on
June 28, 1914. Princip and other nationalists were struggling to end Austro-Hungarian rule over Bosnia and Herzegovina.
The assassination of Franz Ferdinand set off a rapidly escalating chain of events: Austria-Hungary, like many countries
around the world, blamed the Serbian government for the attack and hoped to use the incident as justification for settling the question of Serbian nationalism once and for all.
Kaiser Wilhelm II
Because mighty Russia supported Serbia, Austria-Hungary waited to declare war until its leaders received assurance
from German leader Kaiser Wilhelm II that Germany would support their cause. Austro-Hungarian leaders feared that a
Russian intervention would involve Russia’s ally, France, and possibly Great Britain as well.
On July 5, Kaiser Wilhelm secretly pledged his support, giving Austria-Hungary a so-called carte blanche, or “blank
check” assurance of Germany’s backing in the case of war. The Dual Monarchy of Austria-Hungary then sent an ultimatum to Serbia, with such harsh terms as to make it almost impossible to accept.
World War I Begins
Convinced that Austria-Hungary was readying for war, the Serbian government ordered the Serbian army to mobilize
and appealed to Russia for assistance. On July 28, Austria-Hungary declared war on Serbia, and the tenuous peace
between Europe’s great powers quickly collapsed. Within a week, Russia, Belgium, France, Great Britain and Serbia had lined up against Austria-Hungary and Germany, and World War I had begun.
The Western Front
According to an aggressive military strategy known as the Schlieffen Plan (named for its mastermind, German Field
Marshal Alfred von Schlieffen), Germany began fighting World War I on two fronts, invading France through neutral
Belgium in the west and confronting Russia in the east.
On August 4, 1914, German troops crossed the border into Belgium. In the first battle of World War I, the Germans
assaulted the heavily fortified city of Liege, using the most powerful weapons in their arsenal—enormous siege
cannons—to capture the city by August 15. The Germans left death and destruction in their wake as they advanced
through Belgium toward France, shooting civilians and executing a Belgian priest they had accused of inciting civilian resistance.
First Battle of the Marne
In the First Battle of the Marne, fought from September 6-9, 1914, French and British forces confronted the invading
Germany army, which had by then penetrated deep into northeastern France, within 30 miles of Paris. The Allied troops
checked the German advance and mounted a successful counterattack, driving the Germans back to north of the Aisne River.
The defeat meant the end of German plans for a quick victory in France. Both sides dug into trenches, and the Western
Front was the setting for a hellish war of attrition that would last more than three years.
Particularly long and costly battles in this campaign were fought at Verdun (February-December 1916) and the Battle of
the Somme (July-November 1916). German and French troops suffered close to a million casualties in the Battle of Verdun alone.
The Eastern Front
On the Eastern Front of World War I, Russian forces invaded the German-held regions of East Prussia and Poland, but
were stopped short by German and Austrian forces at the Battle of Tannenberg in late August 1914.
Despite that victory, Russia’s assault had forced Germany to move two corps from the Western Front to the Eastern,
contributing to the German loss in the Battle of the Marne.
Combined with the fierce Allied resistance in France, the ability of Russia’s huge war machine to mobilize relatively
quickly in the east ensured a longer, more grueling conflict instead of the quick victory Germany had hoped to win under the Schlieffen Plan.
From 1914 to 1916, Russia’s army mounted several offensives on World War I’s Eastern Front, but was unable to break through German lines.
Defeat on the battlefield, combined with economic instability and the scarcity of food and other essentials, led to
mounting discontent among the bulk of Russia’s population, especially the poverty-stricken workers and peasants. This
increased hostility was directed toward the imperial regime of Czar Nicholas II and his unpopular German-born wife, Alexandra.
Russia’s simmering instability exploded in the Russian Revolution of 1917, spearheaded by Vladimir Lenin and
the Bolsheviks, which ended czarist rule and brought a halt to Russian participation in World War I.
Russia reached an armistice with the Central Powers in early December 1917, freeing German troops to face the remaining Allies on the Western Front.
America Enters World War I
At the outbreak of fighting in 1914, the United States remained on the sidelines of World War I, adopting the policy of
neutrality favored by President Woodrow Wilson while continuing to engage in commerce and shipping with European
countries on both sides of the conflict.
Neutrality, however, was increasing difficult to maintain in the face of Germany’s unchecked submarine aggression
against neutral ships, including those carrying passengers. In 1915, Germany declared the waters surrounding the
British Isles to be a war zone, and German U-boats sunk several commercial and passenger vessels, including some U.S. ships.
Widespread protest over the sinking by U-boat of the British ocean liner Lusitania—traveling from New York to
Liverpool, England with hundreds of American passengers onboard—in May 1915 helped turn the tide of American
public opinion against Germany. In February 1917, Congress passed a $250 million arms appropriations bill intended to make the United States ready for war.
Germany sunk four more U.S. merchant ships the following month, and on April 2 Woodrow Wilson appeared before Congress and called for a declaration of war against Germany.
Battle of the Isonzo
The First Battle of the Isonzo took place in the late spring of 1915, soon after Italy’s entrance into the war on the Allied
side. In the Twelfth Battle of the Isonzo, also known as the Battle of Caporetto (October 1917), German reinforcements
helped Austria-Hungary win a decisive victory.
After Caporetto, Italy’s allies jumped in to offer increased assistance. British and French—and later, American—troops arrived in the region, and the Allies began to take back the Italian Front.
World War I at Sea
In the years before World War I, the superiority of Britain’s Royal Navy was unchallenged by any other nation’s fleet,
but the Imperial German Navy had made substantial strides in closing the gap between the two naval powers. Germany’s strength on the high seas was also aided by its lethal fleet of U-boat submarines.
After the Battle of Dogger Bank in January 1915, in which the British mounted a surprise attack on German ships in the
North Sea, the German navy chose not to confront Britain’s mighty Royal Navy in a major battle for more than a year, preferring to rest the bulk of its naval strategy on its U-boats.
The biggest naval engagement of World War I, the Battle of Jutland (May 1916) left British naval superiority on the
North Sea intact, and Germany would make no further attempts to break an Allied naval blockade for the remainder of the war.
World War I Planes
World War I was the first major conflict to harness the power of planes. Though not as impactful as the British Royal
Navy or Germany’s U-boats, the use of planes in World War I presaged their later, pivotal role in military conflicts around the globe.
At the dawn of World War I, aviation was a relatively new field; the Wright brothers took their first sustained flight just
eleven years before, in 1903. Aircraft were initially used primarily for reconnaissance missions. During the First Battle of
the Marne, information passed from pilots allowed the allies to exploit weak spots in the German lines, helping the
Allies to push Germany out of France.
The first machine guns were successfully mounted on planes in June of 1912 in the United States, but were imperfect; if
timed incorrectly, a bullet could easily destroy the propeller of the plane it came from. The Morane-Saulnier L, a
French plane, provided a solution: The propeller was armored with deflector wedges that prevented bullets from
hitting it. The Morane-Saulnier Type L was used by the French, the British Royal Flying Corps (part of the Army), the
British Royal Navy Air Service and the Imperial Russian Air Service. The British Bristol Type 22 was another popular model used for both reconnaissance work and as a fighter plane.
Dutch inventor Anthony Fokker improved upon the French deflector system in 1915. His “interrupter” synchronized the
firing of the guns with the plane’s propeller to avoid collisions. Though his most popular plane during WWI was the
single-seat Fokker Eindecker, Fokker created over 40 kinds of airplanes for the Germans.
The Allies debuted the Handley-Page HP O/400, the first two-engine bomber, in 1915. As aerial technology progressed,
long-range heavy bombers like Germany’s Gotha G.V. (first introduced in 1917) were used to strike cities like London.
Their speed and maneuverability proved to be far deadlier than Germany’s earlier Zeppelin raids.
By war’s end, the Allies were producing five times more aircraft than the Germans. On April 1, 1918, the British created
the Royal Air Force, or RAF, the first air force to be a separate military branch independent from the navy or army.
World War I Casualties
World War I took the lives of more than 9 million soldiers; 21 million more were wounded. Civilian casualties numbered
close to 10 million. The two nations most affected were Germany and France, each of which sent some 80 percent of their male populations between the ages of 15 and 49 into battle.
Legacy of World War I
World War I brought about massive social upheaval, as millions of women entered the workforce to replace men who
went to war and those who never came back. The first global war also helped to spread one of the world’s deadliest
global pandemics, the Spanish flu epidemic of 1918, which killed an estimated 20 to 50 million people.
World War I has also been referred to as “the first modern war.” Many of the technologies now associated with military
conflict—machine guns, tanks, aerial combat and radio communications—were introduced on a massive scale during World War I.
The severe effects that chemical weapons such as mustard gas and phosgene had on soldiers and civilians during
World War I galvanized public and military attitudes against their continued use. The Geneva Convention agreements,
signed in 1925, restricted the use of chemical and biological agents in warfare and remains in effect today.
By Cynthia N.