Events
1071 - Bari falls to Robert Guiscard, ending Byzantine rule in Italy.
1346 - The Serbian Empire is proclaimed in Skopje by Dusan Silni, occupying much of the Balkans.
1521 - Martin Luther's first appearance before the Diet of Worms to be examined by the Holy Roman Emperor Charles V and the other estates of the empire.
1582 - Spanish conquistador Hernando de Lerma founds the settlement of Salta, Argentina.
1746 - The Battle of Culloden is fought between the French-supported Jacobites and the Hanoverian British Government.
1780 - The University of Münster in Münster, North Rhine-Westphalia, Germany is founded.
1799 - Napoleonic Wars: The Battle of Mount Tabor – Napoleon drives Ottoman Turks across the River Jordan near Acre.
1853 - The first passenger rail opens in India, from Bori Bunder, Bombay to Thane.
1858 - The Wernerian Natural History Society, a former Scottish learned society, is wound up.
1862 - American Civil War: The Battle at Lee's Mills in Virginia.
1862 - American Civil War: A bill ending slavery in the District of Columbia becomes law.
1863 - American Civil War: The Siege of Vicksburg – ships led by Union Admiral David Dixon Porter move through heavy Confederate artillery fire on approach to Vicksburg, Mississippi.
1881 - In Dodge City, Kansas, Bat Masterson fights his last gun battle.
1910 - The University of Queensland is founded, with the names of the members of the first Senate published in the Queensland Government Gazette.
1912 - Harriet Quimby becomes the first woman to fly an airplane across the English Channel.
1917 - Lenin returns to Petrograd from exile in Switzerland.
1919 - Gandhi organizes a day of "prayer and fasting" in response to the killing of Indian protesters in the Amritsar Massacre by the British.
1922 - The Treaty of Rapallo, pursuant to which Germany and the Soviet Union re-establish diplomatic relations, is signed.
1925 - During the Communist St Nedelya Church assault in Sofia, 150 are killed and 500 are wounded.
1941 - World War II: The Italian convoy Duisburg, directed to Tunisia, is attacked and destroyed by British ships.
1941 - Bob Feller of the Cleveland Indians throws the only Opening Day no-hitter in the history of Major League Baseball, beating the Chicago White Sox 1-0.
1943 - Dr. Albert Hofmann discovers the psychedelic effects of LSD.
1945 - The Red Army begins the final assault on German forces around Berlin.
1945 - The United States Army liberates Nazi Sonderlager (high security) Prisoner of War camp Oflag IV-C (better known as Colditz).
1945 - More than 7,000 die when the German refugee ship Goya is sunk by a Soviet submarine torpedo.
1946 - Syria gains independence.
1947 - Texas City Disaster: An explosion on board a freighter in port causes the city of Texas City, Texas, to catch fire, killing almost 600.
1947 - Bernard Baruch coins the term "Cold War" to describe the relationship between the United States and the Soviet Union.
1953 - Queen Elizabeth II launches the Royal Yacht HMY;Britannia.
1963 - Dr. Martin Luther King, Jr. pens his famous Letter from Birmingham Jail while incarcerated in Birmingham, Alabama for protesting against segregation.
1972 - Apollo program: The launch of Apollo 16 from Cape Canaveral, Florida.
1987 - British Conservative MP Harvey Proctor appears at Bow Street Magistrates' Court in London charged with gross indecency.
1990 - The "Doctor of Death", Jack Kevorkian, goes through with his first assisted suicide.
1992 - The Katina P. runs aground off of Maputo, Mozambique. 60,000 tons of crude oil spill into the ocean.
2003 - The Treaty of Accession is signed in Athens admitting 10 new member states to the European Union.
2004 - The super liner Queen Mary 2 embarks on her first trans-Atlantic crossing, linking the golden age of ocean travel to the modern age of ocean travel.
2007 - Virginia Tech massacre: The deadliest mass shooting in modern American history. The gunman, Seung-Hui Cho, shoots 32 people to death and injures 23 others before committing suicide.
2008 - Democratic senators Hillary Rodham Clinton of New York and Barack Obama of Illinois participate in a presidential debate at the National Constitution Center in Philadelphia. The ABC-sponsored event is the final Democratic primary debate of 2008, and takes place the eve of Clinton's victories in Texas and Ohio before her eventual concession on June 7th.