| 10 October 333 BC | Greece, Syria, Persian Empire [campaigns of Alexander the Great (334–323 BC)] | Alexander the Great of Macedon defeats King Darius III of Persia at Issus in southeast Cilicia and becomes master of Syria. Darius flees; his family are captured but treated well by Alexander. The Greeks send congratulations and a golden crown. |
| 10 October 40 BC | Rome [treaties] | The Pact of Brundisium is arranged by the Roman triumvir Octavian's friend Maecenas, reconciling the three members of the Second Triumvirate and slightly rearranging their territories and commands of troops. Transalpine Gaul is removed from Mark Antony and given to Octavian. Marcus Aemilius Lepidus remains with Africa. Octavian gives his sister Octavia in marriage to Mark Antony to help cement the alliance again. |
| 10 October 974 | Italy, Holy Roman Empire [political events] | Benedict VII is crowned as pope in Rome, Italy. |
| 10 October 978 | France [political events] | The Holy Roman Emperor, Otto II of Germany, invades France, harrying as far as Paris, in retaliation for an attempt by King Lothair IV of France to seize Lorraine. |
| 10 October 1154 | Holy Roman Empire, Italy, Papal States [diplomacy] | King Frederick I Barbarossa of Germany begins an expedition to Italy to restore royal authority there after the disorders of the ‘Investiture Contest’ (conflict between the papacy and the Empire over lay investiture of senior churchmen) and its aftermath. |
| 10 October 1176 | Holy Roman Empire, Italy [diplomacy] | By the Treaty of Anagni, the Holy Roman Emperor Frederick I Barbarossa recognizes Alexander III as the legitimate pope, so ending the schism between the empire and the papacy. |
| 10 October 1189 | Holy Roman Empire, Saxony, Germany [political events] | With the Holy Roman Emperor Frederick I Barbarossa absent on crusade, Henry the Lion, the dispossessed Duke of Saxony and Bavaria, returns to Germany and recovers much of Saxony and Holstein. |
| 10 October 1204 | Latin Empire of Constantinople, Venice, Italy, Byzantine Empire [political events] | The Latin emperor Baldwin of Constantinople, the Venetians, and the crusaders partition the Byzantine Empire by treaty. Continuing Byzantine resistance, however, means that many of the crusaders are unable to take possession of their territories. |
| 10 October 1214 | Castile, Spain [political events] | King Alfonso VIII of Castile dies; he is succeeded by his son, Henry I, a minor; civil war follows. |
| 10 October 1253 | Germany, Sicily, Naples, Italy [political events] | King Conrad IV of Germany and Sicily completes his suppression of a Sicilian rebellion with the recovery of the Italian kingdom of Naples. |
| 10 October 1254 | England, Castile, León, Spain, Gascony, France [political events] | Edward Plantagenet, the son of King Henry III of England, marries Eleanor, the sister of King Alfonso X of Castile and León. This helps seal the peace between Alfonso and Henry and ensures English control of Gascony: Prince Edward is endowed with Gascony and resides there. |
| 10 October 1365 | Mameluke Sultanate, Egypt, Cyprus [wars] | A crusade led by King Peter I of Cyprus takes Alexandria, in Mameluke Egypt. He departs after sacking the town and massacring its population. |
| 10 October 1369 | Italy, Byzantine Empire [wars] | The Byzantine emperor John V Palaeologus visits Rome, Italy, on a mission to solicit aid against the Ottoman Turks, and is accepted into the Roman church. |
| 10 October 1500 | Portugal, Spain [political events] | King Manuel I of Portugal marries the infanta Maria of Spain, sister of his dead wife and fourth daughter of King Ferdinand II of Aragon and Queen Isabella I of Castile, whose hopes of a dynastic union of the kingdoms are thus revitalized. |
| 10 October 1813 | Parma [births and deaths] | Giuseppe Fortunino Francesco Verdi, Italian operatic composer, born in Le Roncole, near Busseto, Duchy of Parma (–1901). |
| 10 October 1825 | Southern Africa [births and deaths] | Paul Kruger, Boer statesman who founds the Afrikaaner nation and is instrumental in initiating the Second Anglo-Boer War, born in Cradock district, Cape Colony, Southern Africa (–1904). |
| 10–14 October 1829 | England [railways] | George and Robert Stephenson's Rocket wins the Liverpool and Manchester Railway competition with an average speed of 58 kph/36 mph without a load, and 26 kph/16 mph with a 40 tonne load. Using a multiple fire-tube boiler, rather than the single flue boiler other contestants use, its design sets the pattern for future railway locomotives. |
| 10 October 1842 | Afghanistan, UK [wars] | The First Anglo-Afghan War, begun by a British invasion in 1839 to counter perceived Russian and Persian expansionism in the region, ends in British defeat. After the massacre of over 3,000 British and Indian troops retreating from a popular revolt in Kabul in January, a punitive expedition reoccupying the country is withdrawn by the British government. |
| 10 October 1846 | Spain, France [political events] | Queen Isabella II of Spain is married to the Duke of Cadiz, Don Francisco de Asis, while her sister Princess Maria Louisa Fernanda marries the duc de Montpensier, the youngest son of the French king, Louis Philippe, giving France undue influence in Spain. Fears of British opposition to the marriages weaken the Orléanist monarchy in France. |
| 10 October 1850 | China [political events] | The Taiping Rebellion breaks out in China under Hong Xiuquan, who takes the cities of Nanjing and Shanghai, proclaims himself emperor, and attacks Beijing. |
| 10 October 1857 | UK, USA [political parties] | The Irish Republican Brotherhood (whose members are known as Fenians) is founded in New York City to fight for Irish independence from Britain |
| 10 October 1922 | Iraq, UK [political events] | The formal British mandate over Iraq is ended and an alliance between the two is concluded. |
| 10 October 1939 | USSR, Lithuania [diplomacy] | The USSR signs a pact with Lithuania allowing Soviet troops to be stationed on Lithuanian territory (and in effect reducing the Baltic state to a Soviet colony). The city of Vilna (now Vilnius), formerly in Poland but taken by the USSR on 28 September, is returned to Lithuania. |
| 10 October 1955 | UK [television] | The British Broadcasting Corporation (BBC) begins to make experimental colour broadcasts. |
| 10 October 1957 | England [energy] | A fire in a military reactor producing plutonium at the English nuclear facility Windscale (now Sellafield) releases large amounts of radioactivity into the surrounding area, news of which is suppressed by the UK government. |
| 10 October 1964 | USA, Japan [television] | US satellites Syncom 3 (launched 19 August 1964) in a synchronous orbit 37,000 km/23,000 mi above the Pacific Ocean, transmits the opening ceremonies of the Tokyo Olympics, the first transpacific television pictures. |
| 10 October 1967 | UK [legislation] | The Road Safety Act introduces breathalyser tests in Britain to check the blood alcohol level of drivers. |
| 10 October 1970 | Pacific [decolonization] | Fiji Islands becomes independent within the British Commonwealth. |
| 10 October 1985 | USA [births and deaths] | Orson Welles, US film actor, director, producer, and writer, best known for Citizen Kane, dies in Los Angeles, California (70). |
| 10 October 2000 | Sri Lanka [births and deaths] | Sirimavo Bandaranaike, the world's first woman prime minister, dies in Sri Lanka (84). |
| 10 October 2003 | Australia [cricket] | Australian cricketer Matthew Hayden scores 380 runs in a Test match innings against Zimbabwe in Perth, breaking the previous record of 375 for the highest ever individual score in international cricket. |
| 10 October 2003 | [human rights] | Shirin Ebadi, an Iranian lawyer and human rights campaigner, wins the Nobel Prize for Peace. She is the first Muslim woman to receive the award. |
