| 30 October 1281 | Mameluke Sultanate, Armenia, Ilkhanate, Syria [wars] | The Mameluke sultan of Egypt, Qalawun, defeats the Mongols, Armenians, and Knights Hospitallers (members of an order of Christian chivalry) at Homs, Syria, after a failure by the Ilkhan of Persia to persuade Pope Martin IV to order a crusade against the Mamelukes. |
| 30 October 1340 | Spain, Portugal, Africa [wars] | King Alfonso XI of Castile and King Afonso IV of Portugal defeat a Muslim invasion from Africa on the River Salado. |
| 30 October 1422 | France [political events] | The dauphin Charles, son of the late king Charles VI of France, assumes the title of King (Charles VII) of France, in defiance of the 1420 Treaty of Troyes by which King Henry VI of England is the successor to the French throne. |
| 30 October 1735 | USA [births and deaths] | John Adams, first vice-president 1778–97 and second president 1797–1801 of the USA, a Federalist, born in Braintree, Massachusetts (–1826). |
| 30 October 1864 | Austrian Empire, Prussia, Denmark [treaties] | The Peace of Vienna concludes the German-Danish war, by which Denmark cedes the duchies of Schleswig, Holstein, and Lauenburg to Austria and Prussia. |
| 30 October 1885 | USA [births and deaths] | Ezra Pound, US poet and literary critic, born in Hailey, Idaho (–1972). |
| 30 October 1905 | Russian Empire [law and government] | Tsar Nicholas II of Russia issues the ‘October Manifesto’, capitulating to demands for the duma (parliament) to have legislative powers and a wider franchise for its election, and civil liberties. |
| 30 October 1956 | Hungary, USSR [diplomacy] | The Hungarian prime minister Imre Nagy promises free elections in Hungary, and Cardinal Mindszenty is released following eight years of captivity. The USSR responds by sending Soviet and satellite state troops to invade Hungary. |
| 30 October 1961 | Italy [births and deaths] | Luigi Einaudi, first president of the Republic of Italy (1948–55), dies in Rome, Italy (87). |
| 30 October 1982 | Portugal [law and government] | A new Portuguese constitution comes into force, ending military influence in government. |
| 30 October 1995 | USA [statistics and demography] | A survey finds that 17% of adults in the USA and Canada have access to the Internet and that 11% of adults have used the Internet in the previous three months. The survey also finds that two-thirds of Internet users are men. |
