May 20

• May 20, 526
  An earthquake kills 250,000 in Syria and the city of Antioch in the Byzantine Empire and causes severe damage to many of the buildings
• May 20, 685
  Picts, a tribal confederation of Celtic tribes, defeat forces of Northumbria at the Battle of Dun Nechtain ending the dominance of Angles in Northern Britain
• May 20, 1303
  Treaty of Paris restores Gascony to British setting the stage for the Hundred Years' War
• May 20, 1347
  Cola di Rienzo, an Italian politician and popular leader, takes the title of tribune in Rome
• May 20, 1498
  Vasco de Gama, a Portuguese explorer, reaches Kozhikode, India by sea completing his journey that took him around South Africa and opens the Far East to European trade and colonial expansion
• May 20, 1506
  Christopher Columbus, explorer, dies in poverty in Valladolid, Spain at age 55
• May 20, 1571
  Pope Pius V completes the Holy League as a united front against the Ottoman Turks
• May 20, 1631
  Forces of the Holy Roman Empire and the Catholic League under earl Johann Tilly conquer Magdeburg, beginning the subsequent plundering, and the massacre of the inhabitants of the largely Protestant city
• May 20, 1648
  In Poland King Władysław IV Vasa dies at age 55 and his Jesuit brother takes rule as John II Casimir
• May 20, 1774
  Britain set procedures of governance in the Province of Quebec by Quebec Act
• May 20, 1775
  Mecklenburg County, North Carolina becomes the first part of the Thirteen Colonies to declare independence from Great Britain
• May 20, 1784
  Preliminary signed 2 September 1783 Peace of Paris ends the war between England and Netherlands and ends Fourth Anglo-Dutch War
• May 20, 1799
  Napoleon Bonaparte orders a withdrawal from his siege of city of Acre in Ottoman Empire due to plague which run through besieging French forces
• May 20, 1862
  President Lincoln signs the Homestead Act, providing 1 million km of free land to settlers in the West, which officially opens the Nebraska territory for settlement, leading to statehood in 1867
• May 20, 1867
  Foundation of Royal Albert Hall, a concert hall in London, is laid by Queen Victoria
• May 20, 1873
  Levi Strauss and Jacob Davis receive a US patent for "Improvement in Fastening Pocket-Openings", work pants reinforced with metal rivets, marking the birth of blue jeans
• May 20, 1875
  International Bureau of Weights and Measures, an international standards organisation, is established by treaty among 17 nations
• May 20, 1882
  Triple Alliance between Germany, Italy and Austria-Hungary forms
• May 20, 1902
  Cuba gains independence from the United States after United States military occupation of Cuba ends
• May 20, 1927
  Kingdom of Nejd and Hejaz, modern Saudi Arabia, becomes independent of Great Britain by Treaty of Jeddah between King Abdul Aziz, usually known as Ibn Saud, and the United Kingdom
• May 20, 1940
  Igor Sikorsky, a Russian American aviation engineer, unveils his helicopter invention
• May 20, 1941
  Operation Mercury is launched, as German gliders and 7th Airborne Division paratroopers land near principal airports on Crete, with the mission of securing them for transport of 5th Division troops, however many gliders crash, and many paratroopers are shot in the air
• May 20, 2002
  East Timor regains its independence
• May 20, 2007
  The ruler of Dubai, Sheikh Mohammed bin Rashid al-Maktoum makes the largest single charitable donation in modern history, committing 7.41 billion euros to an educational foundation in the Middle East