May 9

• May 9, 1386
  Treaty of Windsor, the oldest diplomatic alliance in the world which is still in force, is signed between Portugal and England by the marriage of King John I of Portugal to Philippa of Lancaster, daughter of 1st Duke of Lancaster
• May 9, 1502
  Christopher Columbus leaves Cadiz, Spain with four ships on his fourth and final trip to New World, to search for a sea passage to India
• May 9, 1588
  Catholic League troops under duke Henri de Guise occupies Paris, France
• May 9, 1671
  Thomas Blood, Irish adventurer, attempts to steal the Crown Jewels from the Tower of London
• May 9, 1754
  The first American newspaper cartoon, a snake cut into sections, each part representing an American colony, is published with caption "Join or die" in Benjamin Franklin's Pennsylvania Gazette
• May 9, 1785
  British inventor Joseph Bramah patents a beer pump
• May 9, 1864
  Austria and Denmark held a ship battle at Helgoland
• May 9, 1873
  The collapse of the Vienna Stock Exchange, caused by booming stock prices, starts of Panic of 1873, described as the first international crisis, and Long Depression in Western Europe and North America
• May 9, 1901
  Australia opens its first parliament in Melbourne
• May 9, 1926
  Richard Byrd and Floyd Bennett make first flight over North Pole
• May 9, 1927
  Australian Parliament convenes in Canberra for the first time
• May 9, 1936
  Italy takes Addis Ababa, annexing Abyssinia and incorporates it with Italian Somaliland and Italian Eritrea into the new colony of Italian East Africa
• May 9, 1941
  English Army breaks German spy codes
• May 9, 1944
  Russians recapture Crimea by taking Sevastopol
• May 9, 1950
  French Foreign minister Robert Schuman announces the Schuman Plan for European integration, which led to the creation of the European Coal and Steel Community
• May 9, 1955
  German Federal Republic joins NATO
• May 9, 1978
  In Rome, the corpse of former Italian prime minister Aldo Moro, kidnapped on March 16, is found in a red Renault 4 automobile
• May 9, 1979
  The Salvadoran Civil War begins between the military-led government of El Salvador and coalition or 'umbrella organization' of five left-wing guerrilla groups
• May 9, 1993
  Juan Carlos Wasmosy becomes the first democratically elected President of Paraguay in 50 years
• May 9, 2004
  Chechen president Akhmad Kadyrov is killed by a landmine placed under a VIP stage during a World War II memorial parade in Grozny