February 27

• February 27, 425
  Byzantine Emperor Theodosius II founds the University of Constantinople
• February 27, 1531
  German evangelical monarchy joins Schmalkaldic League, a defensive alliance of Lutheran princes within the Holy Roman Empire
• February 27, 1670
  Jews are expelled from Vienna by order of Leopold I
• February 27, 1861
  In the Warsaw massacre Russian troops fire on a crowd protesting Russian rule over Poland and kill five marchers
• February 27, 1879
  Constantin Fahlberg discovers saccharin, artificial sweetener
• February 27, 1883
  Oscar Hammerstein I, a businessman and composer in New York City, patents first cigar-rolling machine
• February 27, 1906
  France and Britain agree to joint control of New Hebrides, an island group in the South Pacific
• February 27, 1940
  Martin Kamen and Sam Ruben discover carbon-14, creating the basis for the radiocarbon dating method
• February 27, 1956
  Female suffrage in Egypt
• February 27, 1957
  Chinese Chairman Mao's speech "On the Correct Handling of Contradictions Among People", marking the start of Hundred Flowers Campaign, a campaign encouraging its citizens to openly express their opinions of the communist regime
• February 27, 1972
  US President Richard Nixon and Chinese Premier Zhou Enlai issue Shanghai Communique, pledging that it is in the interest of all nations for the United States and China to work towards the normalization of their relations
• February 27, 1980
  M-19 guerrillas begin the Dominican embassy siege in Colombia, holding 60 people hostage, including 14 ambassadors
• February 27, 2012
  Yemeni President Ali Abdullah Saleh is succeeded by Vice President Abd Rabbuh Mansur Al-Hadi as a result of Yemeni Revolution

February 23

• February 23, 155
  Polycarp, Christian bishop of Smyrna, is arrested and burned at stake
• February 23, 1100
  Emperor Huizong, a calligrapher, painter and promoter of Taoism, begins to rule over China
• February 23, 1516
  The Hapsburg Charles I is proclaimed king of Aragon and Castile after the death of his grandfather Ferdinand II
• February 23, 1530
  Spain's King Carlos I is crowned Holy Roman Emperor Charles V by Pope Clement VII in the last coronation of a German king by a Pope
• February 23, 1574
  The 5th War of Religion, against the Huguenots, breaks out in France
• February 23, 1615
  The Estates-General in Paris are dissolved, having been in session since October 1614
• February 23, 1660
  Charles XI becomes king of Sweden after death of his father Charles X Gustav of a stroke
• February 23, 1685
  George Frideric Handel, composer and musician, is born in Halle, Germany
• February 23, 1689
  Protestant Dutch prince William III ascends to the throne over England, Scotland, and Ireland after King James II, Catholics protector, escape during England's Glorious Revolution
• February 23, 1820
  Cato Street Conspiracy, an attempt to murder all the British cabinet ministers and Prime Minister Lord Liverpool, is uncovered
• February 23, 1847
  American major general Zachary Taylor defeats Mexican General Antonio Loіpez de Santa Anna and Mexican army at the battle of Buena Vista, Mexico
• February 23, 1848
  Revolution of 1848 begins in France resulting in King Louis-Philippe's abdication, the establishment of the Second French Republic and spread of revolutionary movements throughout Europe
• February 23, 1854
  Great Britain and Orange Free state sign Convention of Bloemfontein, by which the independence of the Orange Free State is recognized
• February 23, 1893
  Rudolf Diesel, a German mechanical engineer, is granted a patent for the invention of the diesel engine, an internal combustion engine that uses the heat of compression to initiate ignition
• February 23, 1987
  Supernova 1987A, the first naked-eye supernova since 1604, first seen in Large Magellanic Cloud
• February 23, 1998
  Osama bin Laden publishes a fatwa, declaring jihad against all Jews and Crusaders, which declared the killing of North Americans and their allies
• February 23, 2002
  Revolutionary Armed Forces of Colombia kidnaps Oxygen Green Party presidential candidate Ingrid Betancourt, who is traveling in Colombian territory
• February 23, 2008
  Microsoft announces it will cease making HD DVD players for the Xbox 360