| 14 August 1018 | Kiev [political events] | King Boleslaw of Poland enters Kiev, Russia, and restores his son-in-law Sviatopolk I to the throne, but is then forced to retire when Sviatopolk organizes an anti-Polish rising. Boleslaw, however, retains Czerwien and Przemysl for Poland. |
| 14 August 1431 | Bohemia, Holy Roman Empire [wars] | A crusading army led by Cardinal Cesarini flees from Domažlice, Bohemia, on the approach of the Bohemians: the fifth anti-Hussite crusade fails. |
| 14 August 1733 | Poland, Russia, Holy Roman Empire, France [War of the Polish Succession (1733–38)] | The War of the Polish Succession begins. Russia and the Holy Roman Emperor Charles VI recognize the elector Augustus III of Saxony as ruler of Poland whereas France supports the claim of former king Stanislaw Leszczynski. |
| 14 August 1834 | UK [welfare] | The Poor Law Amendment Act in Britain revises the provision of relief to the unemployed and elderly, establishing workhouses where conditions are to be made hard in order that only the truly needy will submit themselves to them. |
| 14 August 1865 | Austrian Empire, Prussia, Denmark [treaties] | The Convention of Gastein temporarily resolves the question of the administration of the duchies of Schleswig and Holstein (ceded to Austria and Prussia by Denmark). Austria receives Holstein and Prussia obtains Schleswig and the port city of Kiel, while purchasing the duchy of Lauenburg. |
| 14 August 1912 | Bulgaria, Serbia, Anatolia, Ottoman Empire [Balkan wars (1912–13)] | As a pretext for war, Bulgaria demands autonomy for Macedonia from the Ottoman Empire. |
| 14–16 August 1920 | Poland, Russia [wars] | Polish forces under Joseph Pilsudski defeat the advancing Russian troops led by Michael Tukhachevski at Warsaw, Poland. |
| 14 August 1920 | Kingdom of the Serbs Croats and Slovenes, Czechoslovakia, Romania [diplomacy] | The Kingdom of the Serbs, Croats, and Slovenes and Czechoslovakia make an alliance (and are joined in 1921 by Romania) to form the ‘Little Entente’, a defensive measure against Hungarian revanchism (a policy aimed at regaining lost territories). |
| 14 August 1935 | USA [legislation] | The Social Security Act is enacted in the USA. It provides for old-age pensions, help for the disabled, and unemployment assistance (from 1942), paid for by contributions rather than from tax revenues. The act also provides states with matching grants to help them care for dependent mothers and children. |
| 14 August 1941 | UK, USA [human rights] | The British prime minister Winston Churchill and the US president Franklin D Roosevelt meet at the Placentia Bay conference on board the US cruiser Augusta. They sign the Atlantic Charter, condemning territorial changes and affirming human rights, which subsequently becomes the basis of the United Nations (UN) Declaration of Human Rights. |
| 14 August 1945 | Japan [World War II (1939–45)] | The Japanese emperor Hirohito proclaims Japan's acceptance of the Allies' terms for ending World War II in the Pacific and urges his people to accept the surrender. |
| 14 August 1974 | Greece, Turkey [political events] | Greece withdraws its armed forces from the North Atlantic Treaty Organization (NATO) in protest at its failure to oppose the Turkish ‘menace to world peace’ following the Turkish invasion of Cyprus. |
| 14 August 2003 | USA Canada [energy] | One of the worst-ever power failures in North America blacks out the northeastern USA and Canada for hours, prompting government investigations into the US electricity supply system. |
