Today:
336: Saint Mark is elected as the Catholic Pope, succeeding Pope Sylvester I.
1486: King Henry VII of England marries Elizabeth of York, daughter of Edward IV, effectively uniting the House of Lancaster and the House of York to end the Wars of the Roses.
1535: Spanish conquistador Francisco Pizarro founds the city of Lima, Peru, which he names Ciudad de los Reyes (City of the Kings).
1778: Captain James Cook becomes the first known European to reach the Hawaiian Islands, which he names the Sandwich Islands.
1871: Wilhelm I is proclaimed the first German Emperor in the Hall of Mirrors at the Palace of Versailles, marking the unification of Germany.
1896: The first public demonstration of an X-ray machine is held by H.L. Smith in the United States, following Wilhelm Röntgen’s discovery of X-rays the previous year.
1911: American pilot Eugene B. Ely performs the first successful aircraft landing on a ship, touching down on the deck of the USS Pennsylvania in San Francisco Bay.
1919: The Paris Peace Conference opens at Versailles to set the peace terms for the Central Powers following the end of World War I.
1943: During World War II, the Soviet Union announces that it has broken the Nazi siege of Leningrad, opening a narrow land corridor to the city.
1993: Martin Luther King Jr. Day is officially observed for the first time in all 50 United States.