June 30

• June 30, 827
  The allied fleets of Muslims lands in southwestern Sicily beginning the Muslim conquest of Sicily
• June 30, 1097
  The Crusaders defeat the Turks at Battle of Dorylaeum
• June 30, 1520
  Moctezuma II is murdered by the Aztec as Spanish conquistadors under Cortez fled the Aztec capital of Tenochtitlan during the night and begin to plunder gold
• June 30, 1859
  French acrobat Charles Blondin crosses Niagara Falls on a tightrope as 5,000 spectators watch
• June 30, 1893
  Excelsior Diamond, the second largest rough diamond of gem quality ever found, is discovered at the Jagersfontein Mine in South Africa
• June 30, 1894
  Tower Bridge, a combined bascule and suspension bridge in London which crosses the River Thames, is opened
• June 30, 1908
  The Tunguska event near Tunguska River in central Siberia, Russia, later conjectured to be a meteorite strike, explodes 5-10 km above the forest and devastates thousands of square kilometers of Siberia
• June 30, 1923
  New Zealand claims Ross Dependency in Antarctica
• June 30, 1960
  Belgian Congo gains independence from Belgium as Republic of the Congo, triggering Congo Crisis, a conflict between nationalist faction under Prime Minister Patrice Lumumba and leader of country Mobutu Sese Seko
• June 30, 1963
  Cardinal Montini elected Pope Paul VI, 262nd head of Roman Catholic Church
• June 30, 1971
  Three cosmonauts die as Soyuz 11 depressurizes during reentry
• June 30, 1997
  Collapse of the currency of Thailand sparks the 1997 Asian Financial Crisis
• June 30, 2002
  Brazil national football team wins its fifth championship at the FIFA World Cup, held in South Korea and Japan

March 23

• March 23, 1026
  Conrad II, King of the Germans, crowns himself king of Italy
• March 23, 1490
  First dated edition of Mishna Torah, a code of Jewish religious law, written by Jewish philosopher Maimonides, is published
• March 23, 1592
  Toyotomi Hideyoshi, Imperial Regent of Japan, sends an army to invade Korea after Korea refused to help him invade China
• March 23, 1791
  Etta Palm d'Aelders, a Dutch champion of woman's rights, set up a group of women's clubs called the Confederation of the Friends of Truth
• March 23, 1801
  Paul I, Tsar of Russia, is strangled in his bedroom in Saint Petersburg ending 4 years of insane rule, and his son Alexander I Pavlovich succeeds him
• March 23, 1808
  Napoleon's brother Joseph takes the throne of Spain
• March 23, 1849
  Forces of Austrian Emprire under Joseph Radetzky von Radetz beat Kingdom of Sardinia in Battle of Novara, after which Charles Albert of Sardinia abdicats in favor of his son, Victor Emmanuel II
• March 23, 1857
  Elisha Otis installs the first modern passenger elevator in the 5-story Haughwout and Co. building at 488 Broadway in New York City
• March 23, 1875
  HMS Challenger, a steam-assisted Royal Navy Pearl-class corvette, surveys the deepest point in the Earth's oceans, the Challenger Deep
• March 23, 1881
  Boers and Britain sign a peace accord which ends the first Boer war and recognizes South African Republic and Orange Free State
• March 23, 1903
  Wright brothers obtain airplane patent
• March 23, 1919
  The Italian National Fascist Party, consisting of 200 members, is established by Benito Mussolini
• March 23, 1935
  The Philippines are granted Commonwealth status with Manuel Quezon as president, who designates a national language and introduces women's suffrage and land reform
• March 23, 1956
  Pakistan adopted a new constitution, becoming an Islamic republic, and gets full independence
• March 23, 1976
  International Bill of Rights, ratified by 35 nations, goes into effect
• March 23, 1983
  Barney Clar, first artificial heart recipient, dies after 112 days at age 62
• March 23, 1991
  Sierra Leone Civil War begins after the Revolutionary United Front intervened in Sierra Leone in an attempt to overthrow the Joseph Momoh government
• March 23, 1996
  Lee Teng-hui is re-elected in first direct elections for president in the Republic of China on Taiwan
• March 23, 1999
  NATO engages in 78-day bombing campaign against Serbia for occupation of Kosovo