May 31 is the 151st day of the year in the Gregorian calendar (152nd in leap years), with 214 days remaining.

  1. 1279 BC - Ramesses II (The Great) (19th dynasty) becomes pharaoh of Ancient Egypt.
  2. 1223 - Mongol invasion of the Cumans: Battle of the Kalka River - Mongol armies of Genghis Khan lead by Subutai defeat Kievan Rus, Kipchaks, Cumans, and Volga Bulgars warriors under Mstislav the Bold.
  3. 1578 - Martin Frobisher sails from Harwich, England to Frobisher Bay, Canada, eventually to mine fool's gold, used to pave streets in London.
  4. 1669 - Citing poor eyesight, Samuel Pepys records the last event in his diary.
  5. 1678 - The Godiva procession through Coventry begins.
  6. 1759 - The Province of Pennsylvania bans all theater productions.
  7. 1775 - American Revolutionary War: The Mecklenburg Resolutions adopted urging the American Colonies to declare independence from Great Britain.
  8. 1790 - Alferez Manuel Quimper explores the Strait of Juan de Fuca.
  9. 1790 - The United States enacts its first copyright statute, the Copyright Act of 1790.
  10. 1813 - In Australia, Lawson, Blaxland and Wentworth, reached Mount Blaxland, effectively marking the end of a route across the Blue Mountains.
  11. 1862 - American Civil War Peninsula Campaign: Battle of Seven Pines or (Battle of Fair Oaks) - Confederate forces under Joseph E. Johnston & G. W. Smith engage Union forces under George B. McClellan outside Richmond, Virginia.
  12. 1864 - American Civil War Overland Campaign: Battle of Cold Harbor - The Army of Northern Virginia under Robert E. Lee engages the Army of the Potomac under Ulysses S. Grant & George G. Meade.
  13. 1866 - In the Fenian Invasion of Canada, John O'Neill leads 850 Fenian raiders across the Niagara River at Buffalo, New York/Fort Erie, Ontario, as part of an effort to free Ireland from the English. Canadian militia and British regulars repulse the invaders in over the next three days, at a cost of 9 dead and 38 wounded to the Fenian's 19 dead and about 17 wounded.
  14. 1884 - John Harvey Kellogg patents corn flakes.
  15. 1889 - Johnstown Flood: Over 2,200 people die after a dam break sends a 60-foot (18-meter) wall of water over the town of Johnstown, Pennsylvania.
  16. 1902 - Second Boer War: The last Afrikaner resistance forces sign a peace treaty with the British at Pretoria, ending the war, and ensuring British control of South Africa.
  17. 1910 - Creation of the Union of South Africa.
  18. 1911 - R.M.S. Titanic launched.
  19. 1916 - World War I: Battle of Jutland - The British Grand Fleet under the command of Sir John Jellicoe & Sir David Beatty engage and defeat the Kaiserliche Marine under the command of Reinhard Scheer & Franz von Hipper in the largest naval battle of the war.
  20. 1921 - Tulsa Race Riot: A civil unrest in Tulsa, Oklahoma, USA, the official death toll is 39, but recent investigations suggest the actual toll may be much higher.
  21. 1921 - Comedian Buster Keaton marries actress Natalie Talmadge.
  22. 1924 - The Soviet Union signs an agreement with the Peking government, referring to Outer Mongolia as an "integral part of the Republic of China", whose "sovereignty" therein the Soviet Union promises to respect.
  23. 1927 - The last Ford Model T rolls off the assembly line after a production run of 15,007,003 vehicles.
  24. 1942 - World War II: Imperial Japanese Navy midget submarines begin a series of attacks on Sydney, Australia.
  25. 1952 - Dwight D. Eisenhower retires from active service in the United States Army.
  26. 1961 - Republic of South Africa created.
  27. 1962 - The West Indies Federation dissolves.
  28. 1969 - John Lennon and Yoko Ono record Give Peace a Chance, the first single recorded by a solo Beatle, from their hotel bed.
  29. 1970 - The Ancash earthquake causes a landslide that buries the town of Yungay, Peru; more than 47,000 people are killed.
  30. 1971 - In accordance with the Uniform Monday Holiday Act passed by the U.S. Congress in 1968, observation of Memorial Day occurson the last Monday in May for the first time, rather than on the traditional Memorial Day of May 30.
  31. 1972 - AFC Ajax wins the European Cup, later to become the (UEFA Champions League) for the 2nd straight year.
  32. 1973 - The United States Senate votes to cut off funding for the bombing of Khmer Rouge targets within Cambodia, hastening the end of the Cambodian Civil War.
  33. 1974 - Yom Kippur War: Syria and Israel sign a disengagement agreement to resolve the skirmishes and exchanges of artillery fire that had occurred frequently along the Israeli-Syrian cease-fire line.
  34. 1977 - The Trans-Alaska Pipeline System completed.
  35. 1985 - The US-Canadian Outbreak: Forty-one tornadoes hit Ohio, Pennsylvania, New York, and Ontario, leaving 76 dead.
  36. 1990 - The pilot episode of Seinfeld premieres.
  37. 1997 - The Confederation Bridge opens, linking Prince Edward Island with mainland New Brunswick.
  38. 2002 - The 17th Football World Cup, co-hosted by Japan and South Korea, begins with a 1-0 upset of France by Senegal. The tournament ends on June 30, with Brazil winning a record fifth World Cup title.
  39. 2002 - The United States Secretary of the Navy issued Instruction 10520.6 directing all United States Navy ships to fly the First Navy Jack in honor of those killed in the September 11, 2001 attacks. The ensign will be flown for the duration of the War on Terrorism.
  40. 2002 - A series a major storms blew through Western Pennsylvania, killing 1 person when the Whip pavillion at Kennywood collapses.
  41. 2003 - 1996 Atlanta Olympic bomber Eric Rudolph is captured in Murphy, North Carolina.
  42. 2004 - A foul-up during routine software update at the Royal Bank of Canada leads to a three-day misplacement of 10 million account balances.
  43. 2005 - W. Mark Felt admits in the magazine Vanity Fair that he is the anonymous source Deep Throat in the Watergate scandal.