May 18

• May 18, 1096
  Peasant crusaders from France and Germany begin Pogroms of 1096, the first instance of an antisemitism in Europe touched by the First Crusade, murdering thousands of Jews in Germany
• May 18, 1160
  Eric IX, a King of Sweden, is killed by the Danish lord Magnus Henriksson
• May 18, 1291
  Egyptian Mamluks destroy Acre after a siege of 43 days ending the existence of the Crusader Kingdom of Jerusalem
• May 18, 1604
  England and Spain agree sign the Treaty of London ending the 19 year Anglo-Spanish war
• May 18, 1619
  Hugo Grotius, a Dutch jurist who laid the foundations for international law, based on natural law, is sentenced to life in prison
• May 18, 1652
  Rhode Island try to enact first law declaring slavery illegal
• May 18, 1727
  Peter II Alekseyevich is proclaimed Emperor and Autocrat of All the Russias after death of Catherine I
• May 18, 1803
  Britain declares war on France after General Napoleon Bonaparte continues interfering in Italy and Switzerland, ending Peace of Amiens and starting the Napoleonic Wars and War of the Third Coalition
• May 18, 1804
  The French Senate adopted new national constitution of France, establishing the First French Empire and proclaiming Napoleon Bonaparte emperor
• May 18, 1810
  May Revolution as part of Latin American wars of independence against Napoleonic Spain begins in Buenos Aires, Argentina, which lead to the establishment of a local government, the Primera Junta
• May 18, 1830
  Edwin Beard Budding of England signs an agreement for the manufacture of his invention, the lawn mower, in which he adopts the rotary blade in the cloth industry to grass
• May 18, 1896
  The United States Supreme Court upholds the State of Louisiana Separate Car Act in Plessy vs. Ferguson, and affirms that segregation does not constitute discrimination, establishing the doctrine of "separate but equal"
• May 18, 1899
  The First Hague Peace Conference, proposed by Nicholas II of Russia, is opened in the Netherlands as 26 nations met to ban the destruction or seizure of enemy property with no military value
• May 18, 1900
  Tonga becomes a protected state under a Treaty of Friendship with Britain, when European settlers and rival Tongan chiefs tried to oust the second king
• May 18, 1954
  Supreme Court of the United States unanimously decides the case of Brown v. Board of Education, ordering an end to racial segregation in public schools
• May 18, 1994
  Food and Drug Administration concludes that Flavr Savr, a genetically modified tomato, is safe for food use, making it the first commercially grown genetically engineered food
• May 18, 2000
  Boo.com, one of the greatest dot-com busts in history collapses in London after six months, due to lack of funds