| 91891 | August 14 | Event | 1592 – Imjin War: At the Battle of Hansan Island, the Korean Navy, led by Yi Sun-sin, Yi Eok-gi, and Won Gyun, decisively defeats the Japanese Navy, led by Wakisaka Yasuharu, at Hansan Island. |
| 91892 | August 14 | Event | 1598 – Nine Years' War: Battle of the Yellow Ford: Irish forces under Hugh O'Neill, Earl of Tyrone, defeat an English expeditionary force under Henry Bagenal. |
| 91893 | August 14 | Event | 1720 – The Spanish military Villasur expedition is wiped out by Pawnee and Otoe warriors near present-day Columbus, Nebraska. |
| 91894 | August 14 | Event | 1816 – The United Kingdom formally annexed the Tristan da Cunha archipelago, administering them from the Cape Colony in South Africa. |
| 91895 | August 14 | Event | 1842 – American Indian Wars: Second Seminole War ends, with the Seminoles forced from Florida to Oklahoma. |
| 91896 | August 14 | Event | 1848 – Oregon Territory is organized by act of Congress. |
| 91897 | August 14 | Event | 1880 – Construction of Cologne Cathedral, the most famous landmark in Cologne, Germany, is completed. |
| 91898 | August 14 | Event | 1885 – Japan's first patent is issued to the inventor of a rust-proof paint. |
| 91899 | August 14 | Event | 1888 – An audio recording of English composer Arthur Sullivan's "The Lost Chord", one of the first recordings of music ever made, is played during a press conference introducing Thomas Edison's phonograph in London, England. |
| 91900 | August 14 | Event | 1893 – France becomes the first country to introduce motor vehicle registration. |
| 91901 | August 14 | Event | 1897 – Franco-Hova Wars: The town of Anosimena is captured by French troops from Menabe defenders in Madagascar. |
| 91902 | August 14 | Event | 1900 – The Eight-Nation Alliance occupies Beijing, China, in a campaign to end the bloody Boxer Rebellion in China. |
| 91903 | August 14 | Event | 1901 – The first claimed powered flight, by Gustave Whitehead in his Number 21. |
| 91904 | August 14 | Event | 1911 – United States Senate leaders agree to rotate the office of President pro tempore of the Senate among leading candidates to fill the vacancy left by William P. Frye's death. |
| 91905 | August 14 | Event | 1912 – U.S. Marines invade Nicaragua to support the U.S.-backed government installed there after José Santos Zelaya had resigned three years earlier. |
| 91906 | August 14 | Event | 1914 – World War I: Start of the Battle of Lorraine, an unsuccessful French offensive designed to recover the lost province of Moselle from Germany. |
| 91907 | August 14 | Event | 1916 – Romania declares war on Austria-Hungary, joining the Entente in World War I. |
| 91908 | August 14 | Event | 1921 – Tannu Uriankhai, later Tuvan People's Republic is established as a completely independent country (which is supported by Soviet Russia). |
| 91909 | August 14 | Event | 1933 – Loggers cause a forest fire in the Coast Range of Oregon, later known as the first forest fire of the Tillamook Burn. It is extinguished on September 5, after destroying 240,000 acres (970 km2). |
| 91910 | August 14 | Event | 1935 – Franklin D. Roosevelt signs the Social Security Act, creating a government pension system for the retired. |
| 91911 | August 14 | Event | 1936 – Rainey Bethea is hanged in Owensboro, Kentucky in the last public execution in the United States. |
| 91912 | August 14 | Event | 1937 – Chinese Air Force Day: The beginning of air-to-air combat of the Second Sino-Japanese War and World War II in general, when six Imperial Japanese Mitsubishi G3M bombers are shot down by the Nationalist Chinese Air Force while raiding Chinese air ba |
| 91913 | August 14 | Event | 1941 – World War II: Winston Churchill and Franklin D. Roosevelt sign the Atlantic Charter of war stating postwar aims. |
| 91914 | August 14 | Event | 1945 – Japan accepts the Allied terms of surrender in World War II and the Emperor records the Imperial Rescript on Surrender (August 15 in Japan Standard Time). |
| 91915 | August 14 | Event | 1945 – The Viet Minh launches August Revolution amid the political confusion and power vacuum engulfing Vietnam. |
| 91916 | August 14 | Event | 1947 – Pakistan gains Independence from the British Empire and joins the Commonwealth of Nations. |
| 91917 | August 14 | Event | 1959 – Founding and first official meeting of the American Football League. |
| 91918 | August 14 | Event | 1962 – Two gunmen hijacked a mail truck in Plymouth, Massachusetts, and made off with $1.5 million. |
| 91919 | August 14 | Event | 1967 – UK Marine Broadcasting Offences Act declares participation in offshore pirate radio illegal. |
| 91920 | August 14 | Event | 1969 – Operation Banner: British troops are deployed in Northern Ireland. |