World War I
The first industrialized global conflict, killing an estimated 15–22 million people (roughly 9–11 million military and 6–13 million civilian), and fundamentally redrawing the map of Europe and the Middle East.
Preceding Causes
The assassination of Archduke Franz Ferdinand of Austria-Hungary by Gavrilo Princip in Sarajevo (June 28, 1914) triggered interlocking alliance obligations. Underlying causes included imperial rivalries, the naval arms race between Britain and Germany, nationalist tensions in the Balkans, and rigid mobilization plans that escalated a regional crisis into a continental war.
Ottoman Empire
One of history's most powerful and long-lasting empires, the Ottoman state controlled Anatolia, much of the Middle East, North Africa, and southeastern Europe for over six centuries, serving as the seat of the Islamic Caliphate from 1517.
Scramble for Africa
European powers rapidly colonized virtually all of Africa, with the Berlin Conference of 1884–85 establishing rules for colonial claims — though no Africans were invited or consulted.
Historical Consequences
Collapse of four empires (Ottoman, Austro-Hungarian, Russian, German). The Treaty of Versailles imposed punitive terms on Germany. The League of Nations was created but lacked enforcement power. The war's unresolved grievances and the post-war settlement's failures directly contributed to WWII.
Treaty of Versailles
The peace treaty ending WWI imposed harsh terms on Germany including reparations, territorial losses, and war guilt clause.
Russian Revolution
Two revolutions in 1917 — the February Revolution that overthrew Tsar Nicholas II and the October Revolution in which the Bolsheviks seized power — led to the Russian Civil War and the creation of the Soviet Union (1922).