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Assassination of Archduke Franz Ferdinand
Description: Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, was assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb nationalist.
Significance: Triggered the July Crisis, leading to Austria-Hungary’s declaration of war on Serbia and the activation of European alliances.
Location: Sarajevo, Bosnia and Herzegovina -
July Crisis & Austro-Hungarian Ultimatum
Description: Austria-Hungary issued a harsh ultimatum to Serbia, demanding suppression of anti-Austrian activities. Serbia partially accepted but mobilized its army.
Significance: Diplomatic failure escalated tensions, pushing Europe toward war.
Location: Vienna, Austria-Hungary -
Austria-Hungary Declares War on Serbia
Description: Austria-Hungary declared war on Serbia, marking the official start of World War I.
Significance: Activated the alliance system: Russia mobilized to defend Serbia, Germany supported Austria-Hungary.
Location: Belgrade, Serbia -
Germany Declares War on Russia & France
Description: Germany declared war on Russia (August 1) and France (August 3) under the Schlieffen Plan.
Significance: Expanded the war into a continental conflict.
Location: Berlin, Germany -
Germany Invades Belgium; Britain Enters the War
Description: Germany invaded neutral Belgium to bypass French defenses. Britain declared war in defense of Belgian neutrality.
Significance: Globalized the war, drawing in the British Empire.
Location: Liège, Belgium -
Trench Warfare Begins
Description: Both sides dug elaborate trench systems stretching from Switzerland to the North Sea.
Significance: Symbolized the stalemate and horrific conditions of the Western Front.
Location: Western Front (France/Belgium) -
First Battle of the Marne
Description: Allied forces halted the German advance near Paris using taxis to transport troops.
Significance: Ended Germany’s hopes for a quick victory, leading to trench warfare.
Location: Marne River, France -
Gallipoli Campaign Begins
Description: Allied forces (including ANZAC troops) launched a failed amphibious invasion of Ottoman Turkey.
Significance: Demonstrated the difficulty of attacking the Central Powers’ southern flank.
Location: Gallipoli Peninsula, Turkey -
Sinking of the RMS Lusitania
Description: A German U-boat torpedoed the British passenger ship, killing 1,198, including 128 Americans.
Significance: Turned international opinion against Germany and fueled U.S. entry into the war.
Location: Off the coast of Ireland -
Battle of Verdun Begins
Description: Germany launched a massive offensive to “bleed France white.” The battle lasted 10 months.
Significance: Symbolized the futility and brutality of trench warfare; over 700,000 casualties.
Location: Verdun, France -
Battle of the Somme Begins
Description: British and French forces attacked German lines, suffering 57,000 British casualties on the first day.
Significance: Highlighted the devastating human cost of war; first use of tanks.
Location: Somme River, France -
Zimmermann Telegram Intercepted
Description: Germany proposed a military alliance with Mexico against the U.S. via secret telegram. British intelligence intercepted it.
Significance: Outraged American public opinion, leading to U.S. entry into the war.
Location: London, UK (intercepted) -
Russian February Revolution
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U.S. Enters World War I
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Bolshevik October Revolution
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Treaty of Brest-Litovsk
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German Spring Offensive
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Second Battle of the Marne
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Armistice of Compiègne
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Treaty of Versailles Signed