Today:
180 – Roman Emperor Marcus Aurelius dies, leaving his son Commodus as the sole ruler of the Roman Empire.
432 – According to tradition, Saint Patrick arrives in Ireland as a missionary, marking the origins of Saint Patrick’s Day.
1337 – Edward, the Black Prince, son of King Edward III of England, is born. He would become one of the most successful commanders during the Hundred Years’ War.
1756 – Saint Patrick’s Day is celebrated in New York City for the first time, making it one of the earliest known St. Patrick’s Day celebrations in the American colonies.
1776 – The British evacuate Boston during the American Revolutionary War after General George Washington’s successful siege of the city.
1861 – The Kingdom of Italy is officially proclaimed, unifying most of the Italian states under King Victor Emmanuel II.
1905 – Albert Einstein finishes his paper on the quantum theory of light, introducing the idea of light quanta (photons), a foundation of modern physics.
1948 – The Benelux, France, and the United Kingdom sign the Treaty of Brussels, a precursor to NATO, aimed at mutual defense and cooperation.
1958 – The United States launches Vanguard 1, the second successful satellite to reach orbit and the oldest human-made object still in space.
1992 – A referendum in South Africa overwhelmingly supports ending apartheid, with nearly 69% of white voters approving reforms initiated by President F.W. de Klerk.