| 17 August 1648 | UK [British Civil Wars (1642–51)] | The English parliamentarian commander Oliver Cromwell and the New Model Army defeat the invading Scottish forces, under James, 3rd Marquis and 1st Duke of Hamilton, at the Battle of Preston. |
| 17 August 1740 | Rome [religion] | The Italian churchman Prospero Lambertini is elected Pope Benedict XIV following the death of Pope Clement XII |
| 17 August 1743 | Russia, Sweden [treaties] | The Peace of Åbo ends the territorial war between Russia and Sweden. The treaty cedes south Finland as far as the River Kiümen to Russia. |
| 17 August 1786 | Prussia [births and deaths] | Frederick II the Great, King of Prussia 1740–86, dies in Potsdam, near Berlin, Prussia (74). |
| 17–18 August 1807 | USA [ships and shipping] | US engineer Robert Fulton's paddleboat Steamboat, the first commercial paddle steamer, makes a 240 km/150 mi trial run on the Hudson River from Albany to New York City. Completed in 32 hours (sailing ships take 4 days), averaging 7.6 kph/4.7 mph, it is equipped with side paddles and a Boulton and Watt engine. The following year it is refurbished and renamed the Clermont and begins to ply the Hudson River. |
| 17 August 1836 | Peru, Bolivia [political events] | The Federation of Peru and Bolivia is proclaimed by the Bolivian dictator Andrés de Santa Cruz, creating a more powerful political unit under his control. |
| 17–19 August 1911 | United Kingdom [industrial relations] | British railway workers, led by James Thomas and demanding greater union recognition, paralyse the country by holding the first national railway strike. |
| 17 August 1938 | USA [boxing] | US boxer Henry ‘Homicide Hank’ Armstrong becomes the first boxer to hold three world professional titles simultaneously: featherweight, welterweight, and lightweight. |
| 17 August 1945 | Indonesia, Netherlands [political events] | Indonesian leaders proclaim their country's independence from Dutch rule, but this is rejected by the Netherlands. |
| 17–18 August 1961 | East Germany, West Germany [political events] | East German building workers begin constructing the Berlin Wall, a near-impregnable physical barrier sealing off West Berlin and preventing the escape of East Germans to the West. |
| 17 August 1987 | Germany [births and deaths] | Rudolf Hess, German Nazi leader and deputy of Adolf Hitler, dies in Spandau prison in West Berlin, West Germany, where he had remained imprisoned since World War II (93). |
| 17 August 1988 | Pakistan [political events] | Mohammad Zia-ul-Haq, president of Pakistan 1978–88, who had his predecessor, Lulfiqar Ali Bhutto, executed, is killed in Bahawalpur, Pakistan, when his plane is blown up by an assassin's bomb (64). A state of emergency is declared. |
| 17 August 1999 | Turkey [natural disasters] | An earthquake measuring 7.4 on the Richter scale strikes a densely populated industrial area of northwestern Turkey, near Izmit. The initial death toll rises to 2,000, but will exceed 13,000 by the following week. |
