June 18

• June 18, 860
  Taking advantage from Byzantine-Arab Wars, Vikings from Rus' Khaganate on 200 vessels attack and lay siege of the city of Constantinople
• June 18, 1152
  Friedrich I Barbarossa is crowned Emperor of the Holy Roman Empire by Pope Adrian IV in Rome
• June 18, 1178
  In Canterbury, five men observe explosions on the Moon, likely the origin of lunar crater Giordano Bruno
• June 18, 1429
  French forces under Joan of Arc defeat the main British army at the battle of Patay
• June 18, 1643
  In England the battle of Chalgrove Field during the English Civil War ends with a minor Royalist victory
• June 18, 1685
  Monmouth Rebellion, an attempt to overthrow James II, begins in England
• June 18, 1757
  Austrian army beat Prussia at the Battle of Kolín, Bohemia
• June 18, 1812
  War of 1812 begins as United States declares war against Britain
• June 18, 1815
  Emperor of the French Napoleon, who escaped from exile in island of Elba, is defeated by British commander Wellington at the Battle of Waterloo, which brings a conclusion to the Napoleonic Wars and marks the beginning of a Pax Britannica
• June 18, 1935
  England and Germany sign a naval treaty, limiting the German surface fleet to 35 percent of British tonnage, and submarine fleet to 45 percent
• June 18, 1948
  Long Play, or 33 1⁄3 rpm microgroove vinyl record, is introduced by Columbia Records and becomes a new standard by the record industry
• June 18, 1979
  Jimmy Carter and Leonid Brezhnev sign the SALT II agreement in Vienna
• June 18, 1982
  Argentine military dictator Leopoldo Galtieri resigns, in the wake of his country's defeat in the Falklands War
• June 18, 1983
  Sally Ride becomes the first American woman in space
• June 18, 1989
  Solidarity, a Polish non–communist party-controlled trade union, wins landslide victory over the Communist Party in first free elections in Poland, beginning Revolutions in Central and Eastern Europe and collapse of the Soviet Bloc in Europe