| 29 September 106 BC | Roman Empire [births and deaths] | Pompey, Roman general and statesman, born in Rome (–48 BC). |
| 29 September 1227 | Italy, Holy Roman Empire [political events] | Pope Gregory IX excommunicates the Holy Roman Emperor Frederick II for his failure to fulfil his promise to go on crusade (Frederick has claimed to be too ill). |
| 29 September 1267 | England, Wales [treaties] | By the Treaty of Montgomery, King Henry III of England recognizes Llywelyn ap Gruffydd as prince of Wales and as his vassal. |
| 29 September 1397 | England [political events] | King Richard II of England holds a parliament which condemns the actions of the Lords Appellant in 1387–88. The Earl of Arundel is executed and the Earl of Warwick imprisoned. The Duke of Gloucester has already been murdered. |
| 29 September 1399 | England [administration] | King Richard II of England abdicates and is declared deposed in a quasi-parliamentary assembly. Henry, Duke of Lancaster claims and receives the crown as Henry IV. |
| 29 September 1547 | Spain [births and deaths] | Miguel de Cervantes Saavedra, celebrated Spanish novelist, dramatist, and poet, whose best-known work is Don Quixote (1605, 1615), born in Alcalá de Henares, near Madrid, Spain (–1616). |
| 29 September 1560 | Sweden [political events] | Eric XIV succeeds as king of Sweden on death of Gustavus I Vasa; his half-brothers John and Karl gain autonomy in their duchies. |
| 29 September 1567 | France [French Wars of Religion (1562–80)] | Huguenot (French Protestant) forces under Admiral Gaspard de Coligny and Louis de Bourbon, Prince of Condé, fail in their attempt to seize the young French king Charles IX and his mother Catherine de' Medici at Meaux, France; the royal family, guarded by Swiss mercenaries, flees to Paris, France, which the Huguenots besiege. Many provincial towns are once again under Protestant control. |
| 29 September 1758 | England, France [births and deaths] | Horatio Nelson, British naval commander who won decisive battles against France in the Revolutionary and Napoleonic Wars, born in Burnham Thorpe, Norfolk, England (–1805). |
| 29 September 1833 | Spain [political events] | King Ferdinand VII of Spain dies and is succeeded by his infant daughter Queen Isabella II. |
| 29 September 1902 | [births and deaths] | Emile Zola, French novelist and critic who founded the Naturalist movement, dies in Paris, France (62). |
| 29 September 1972 | Japan, China [political events] | Japan and China agree to end the legal state of war that has existed between them since 1937. |
| 29 September–1 October 1982 | USA [consumer products] | Seven Americans die when cyanide is placed in bottles of Tylenol. The makers of the drug, Johnson and Johnson, recall 264,000 bottles, and new tamper-proof packaging for pharmaceuticals and other products is developed. |