Battle of Adwa: Africa Defeats a European Army

On 29 May 1453, Sultan Mehmed II's Ottoman army breached the walls of Constantinople after a 53-day siege, ending the Byzantine Empire and shifting the balance of world power.

On 14 October 1066, William the Conqueror defeated King Harold II at the Battle of Hastings, changing the English language, legal system, and culture forever.

From 1861 to 1865, the United States fought the bloodiest conflict in its history, a war that killed 620,000 soldiers and ended with the abolition of slavery and the question of what kind of nation America would be.

Fought between 1914 and 1918 across three continents, the First World War killed 20 million people and dismantled four empires, replacing the 19th-century world order with one that no one had wanted or planned.