June 12 is the 163rd day of the year (164th in leap years) in the Gregorian calendar; 202 days remain until the end of the year.
910 – Battle of Augsburg: The Hungarians defeat the East Frankish army under King Louis the Child, using the famous feigned retreat tactic of the nomadic warriors.
1240 – At the instigation of Louis IX of France, an inter-faith debate, known as the Disputation of Paris, starts between a Christian monk and four rabbis.
1381 – Peasants' Revolt: In England, rebels assemble at Blackheath, just outside London.
1418 – Armagnac–Burgundian Civil War: Parisians slaughter sympathizers of Bernard VII, Count of Armagnac, along with all prisoners, foreign bankers, and students and faculty of the College of Navarre.
1429 – Hundred Years' War: On the second day of the Battle of Jargeau, Joan of Arc leads the French army in their capture of the city and the English commander, William de la Pole, 1st Duke of Suffolk.
1550 – The city of Helsinki, Finland (belonging to Sweden at the time) is founded by King Gustav I of Sweden.
1643 – The Westminster Assembly is convened by the Parliament of England, without the assent of Charles I, in order to restructure the Church of England.
1653 – First Anglo-Dutch War: The Battle of the Gabbard begins, lasting until the following day.
1665 – Thomas Willett is appointed the first mayor of New York City.
1758 – French and Indian War: Siege of Louisbourg: James Wolfe's attack at Louisbourg, Nova Scotia, commences.
1772 – French explorer Marc-Joseph Marion du Fresne and 25 of his men killed by Māori in New Zealand.
1775 – American War of Independence: British general Thomas Gage declares martial law in Massachusetts. The British offer a pardon to all colonists who lay down their arms. There would be only two exceptions to the amnesty: Samuel Adams and John Hancock, if captured, were to be hanged.
1776 – The Virginia Declaration of Rights is adopted.
1798 – Irish Rebellion of 1798: Battle of Ballynahinch.
1817 – The earliest form of bicycle, the dandy horse, is driven by Karl von Drais.
1821 – Badi VII, king of Sennar, surrenders his throne and realm to Isma'il Pasha, general of the Ottoman Empire, ending the existence of that Sudanese kingdom.
1830 – Beginning of the Invasion of Algiers: Thiry-four thousand French soldiers land 27 kilometers west of Algiers, at Sidi Ferruch.
1864 – American Civil War, Overland Campaign: Battle of Cold Harbor: Ulysses S. Grant gives the Confederate forces under Robert E. Lee a victory when he pulls his Union troops from their position at Cold Harbor, Virginia and moves south.
1898 – Philippine Declaration of Independence: General Emilio Aguinaldo declares the Philippines' independence from Spain.
1899 – New Richmond tornado: The eighth deadliest tornado in U.S. history kills 117 people and injures around 200.
1900 – The Reichstag approves new legislation continuing Germany's naval expansion program. It provides for construction of 38 battleships over a 20-year period. Germany's fleet will be the largest in the world.
1914 – Massacre of Phocaea: Turkish irregulars slaughter 50 to 100 Greeks and expel thousands of others in an ethnic cleansing operation in the Ottoman Empire.
1921 – Mikhail Tukhachevsky orders the use of chemical weapons against the Tambov Rebellion, bringing an end to the peasant uprising.
1935 – A ceasefire is negotiated between Bolivia and Paraguay, ending the Chaco War.
1938 – The Helsinki Olympic Stadium was inaugurated in Töölö, Helsinki, Finland.
1939 – Shooting begins on Paramount Pictures' Dr. Cyclops, the first horror film photographed in three-strip Technicolor.
1939 – The Baseball Hall of Fame opens in Cooperstown, New York.
1940 – World War II: Thirteen thousand British and French troops surrender to Major General Erwin Rommel at Saint-Valery-en-Caux.
1942 – Anne Frank receives a diary for her thirteenth birthday.
1943 – The Holocaust: Germany liquidates the Jewish Ghetto in Brzeżany, Poland (now Berezhany, Ukraine). Around 1,180 Jews are led to the city's old Jewish graveyard and shot.
1944 – World War II: Operation Overlord: American paratroopers of the 101st Airborne Division secure the town of Carentan, Normandy, France.
1954 – Pope Pius XII canonises Dominic Savio, who was 14 years old at the time of his death, as a saint, making him at the time the youngest unmartyred saint in the Roman Catholic Church. In 2017, Francisco and Jacinta Marto, aged ten and nine at the time of their deaths, are declared saints.
1963 – NAACP field secretary Medgar Evers is murdered in front of his home in Jackson, Mississippi by Ku Klux Klan member Byron De La Beckwith during the civil rights movement.
1963 – The film Cleopatra, starring Elizabeth Taylor and Richard Burton, is released in US theaters. It was the most expensive film made at the time.
1964 – Anti-apartheid activist and ANC leader Nelson Mandela is sentenced to life in prison for sabotage in South Africa.
1967 – The United States Supreme Court in Loving v. Virginia declares all U.S. state laws which prohibit interracial marriage to be unconstitutional.
1975 – India, Judge Jagmohanlal Sinha of the city of Allahabad ruled that India's Prime Minister Indira Gandhi had used corrupt practices to win her seat in the Indian Parliament, and that she should be banned from holding any public office. Mrs. Gandhi sent word that she refused to resign.
1979 – Bryan Allen wins the second Kremer prize for a man-powered flight across the English Channel in the Gossamer Albatross.
1981 – The first of the Indiana Jones film franchise, Raiders of the Lost Ark, is released in theaters.
1982 – Nuclear disarmament rally and concert, New York City.
1987 – The Central African Republic's former emperor Jean-Bédel Bokassa is sentenced to death for crimes he had committed during his 13-year rule.
1987 – Cold War: At the Brandenburg Gate, U.S. President Ronald Reagan publicly challenges Mikhail Gorbachev to tear down the Berlin Wall.
1988 – Austral Líneas Aéreas Flight 46, a McDonnell Douglas MD-81, crashes short of the runway at Libertador General José de San Martín Airport, killing all 22 people on board.
1990 – Russia Day: The parliament of the Russian Federation formally declares its sovereignty.
1991 – Russians first democratically elected Boris Yeltsin as the President of Russia.
1991 – Kokkadichcholai massacre: The Sri Lankan Army massacres 152 minority Tamil civilians in the village of Kokkadichcholai near the eastern province town of Batticaloa.
1993 – An election takes place in Nigeria and is won by Moshood Kashimawo Olawale Abiola. Its results are later annulled by the military Government of Ibrahim Babangida.
1997 – Queen Elizabeth II reopens the Globe Theatre in London.
1999 – Kosovo War: Operation Joint Guardian begins when a NATO-led United Nations peacekeeping force (KFor) enters the province of Kosovo in Federal Republic of Yugoslavia.
2009 – Analog television stations (excluding low-powered stations) switch to digital television following the DTV Delay Act.
2009 – A disputed presidential election in Iran leads to wide-ranging local and international protests.
2014 – Between 1,095 and 1,700 Shia Iraqi people are killed in an attack by the Islamic State of Iraq and the Levant on Camp Speicher in Tikrit, Iraq. It's the second deadliest act of terrorism in history, only behind 9/11.
2016 – Forty-nine civilians are killed and 58 others injured in an attack on a gay nightclub in Orlando, Florida; the gunman, Omar Mateen, is killed in a gunfight with police.
2017 – American student Otto Warmbier returns home in a coma after spending 17 months in a North Korean prison and dies a week later.
2018 – United States President Donald Trump and Kim Jong-un of North Korea held the first meeting between leaders of their two countries in Singapore.
Holidays and observances
Chaco Armistice Day (Paraguay)
Christian feast day:
108 Martyrs of World War II
Basilides, Cyrinus, Nabor and Nazarius
Blessed Hildegard Burjan
Enmegahbowh (Episcopal Church)
First Ecumenical Council (Lutheran)
John of Sahagún
Pope Leo III
June 12 (Eastern Orthodox liturgics)
Dia dos Namorados (Brazil)
Helsinki Day (Finland)
Independence Day, celebrates the independence of the Philippines from Spain in 1898.
June 12 Commemoration (Lagos State)
Loving Day (United States)
Russia Day (Russia)
World Day Against Child Labour, and its related observances:
Children's Day (Haiti)