August 14

• August 14, 554
  Ravenna becomes the seat of the Byzantine governor of Italy, the Exarch
• August 14, 582
  Death of Tiberius II Constantine, emperor of Byzantine
• August 14, 1248
  The foundation stone of Cologne Cathedral, the Gothic church with the largest facade in the world, is laid by Archbishop of Cologne Konrad von Hochstaden
• August 14, 1281
  Typhoon destroys Mongol fleet off the coast of Japan during the second Mongol attempt to conquer Japan
• August 14, 1385
  Portuguese under John I of Portugal defeat Castilians at Aljubarrota and regained independence from Crown of Castile
• August 14, 1385
  Union of Krewo, an act between Poland and Lithuania by which Jogaila, Grand Duke of Lithuania, converts to Christianity in exchange for marriage to the underage reigning Queen Jadwiga of Poland, is signed in Kreva Castle, modern-day Belarus
• August 14, 1457
  Gutenberg's financier Johann Fust and calligrapher Peter Schöffer publish Mainz Psalter, the second major book printed with movable type in the West
• August 14, 1498
  Columbus lands at the mouth of the Orinoco River in Venezuela, a continental landmass of South America
• August 14, 1756
  French commander Louis-Joseph de Montcalm takes Fort Oswego, New England, from the British
• August 14, 1784
  Three Saints Bay, the first Russian settlement in Alaska is established on Kodiak Island by Russian fur trader Grigory Shelikhov
• August 14, 1790
  Sweden and Russian come to peace at Värälä, by which neither side gains any territory and Russia agrees to not interfere with Sweden's constitution
• August 14, 1791
  Haitian slaves, led by voodoo priest Dutty Boukman, gather to plan a revolution
• August 14, 1793
  Republican troops in France lay siege to the city of Lyon
• August 14, 1816
  Great Britain annexes Tristan da Cunha, a group of volcanic islands in the south Atlantic Ocean
• August 14, 1842
  Seminole War ends as Indians remove from Florida to Oklahoma and United States officer William Worth declares the war to be at an end
• August 14, 1880
  Construction of Cologne Cathedral, begun in 1248, is completed
• August 14, 1893
  Paris Police Ordinance, France, issues first driving licenses, includes required test
• August 14, 1900
  Eight-Nation Alliance successfully storm and occupy Beijing after about 2 months of siege of the city during the Boxer Rebellion
• August 14, 1935
  The Social Security Act, signed by United States President Franklin Delano Roosevelt, creates the Social Security system and introduces federal assistance for the elderly
• August 14, 1941
  US President Franklin Roosevelt and British Prime Minister Winston Churchill create the Atlantic Charter, the basis for their wartime alliance, pledging to seek to gain no territory and desire no territory changes outside of the choices of people
• August 14, 1947
  The Muslim majority region, formed by the Partition of India, gain independence from the British Empire as Dominion of Pakistan, which results in the largest mass migration in human history
• August 14, 1971
  Bahrain declares its independence from Britain
• August 14, 1971
  British begin internment without trial in Northern Ireland