| 100021 | September 2 | Death | 2014 – Peter Carter, Nigerian-English diplomat, British Ambassador to Estonia (b. 1956) |
| 100022 | September 2 | Death | 2014 – F. Emmett Fitzpatrick, American lawyer and politician, 20th District Attorney of Philadelphia (b. 1930) |
| 100023 | September 2 | Death | 2014 – Norman Gordon, South African cricketer (b. 1911) |
| 100024 | September 2 | Death | 2014 – Helena Rakoczy, Polish gymnast (b. 1921) |
| 100025 | September 2 | Death | 2014 – Goolam Essaji Vahanvati, Indian lawyer and politician, 13th Attorney General of India (b. 1949) |
| 100026 | September 2 | Death | 2015 – Ephraim Engleman, American rheumatologist, author, and academic (b. 1911) |
| 100027 | September 2 | Death | 2015 – Stan Kane, Scottish-Canadian actor, singer, and painter (b. 1929) |
| 100028 | September 2 | Death | 2015 – Alan Kurdi, Syrian boy (b. 2012) |
| 100029 | September 2 | Death | 2015 – Brianna Lea Pruett, American singer-songwriter, poet, and painter (b. 1983) |
| 100030 | September 2 | Death | 2015 – Simo Salminen, Finnish actor (b. 1932) |
| 100031 | September 2 | Holiday and observance | Christian feast day:Acepsimas of Hnaita and companions (Syriac Orthodox Church)Agricola of AvignonAntoninus of PamiersCastor of AptNonnosusSan Esteban del Rey (Acoma Pueblo)September 2 (Eastern Orthodox liturgics) |
| 100032 | September 2 | Holiday and observance | Democracy Day (Tibet) |
| 100033 | September 2 | Holiday and observance | Independence Day (Transnistria, unrecognized) |
| 100034 | September 2 | Holiday and observance | Independence Day (Nagorno-Karabakh Republic, unrecognized) |
| 100035 | September 2 | Holiday and observance | National Day, celebrates the independence of Vietnam from Japan and France in 1945 |
| 100036 | September 2 | Holiday and observance | Sedantag (German Empire) |
| 100037 | September 2 | Holiday and observance | VJ Day (United States) |
| 100038 | September 3 | Event | 36 BC – In the Battle of Naulochus, Marcus Vipsanius Agrippa, admiral of Octavian, defeats Sextus Pompey, son of Pompey, thus ending Pompeian resistance to the Second Triumvirate. |
| 100039 | September 3 | Event | 301 – San Marino, one of the smallest nations in the world and the world's oldest republic still in existence, is founded by Saint Marinus. |
| 100040 | September 3 | Event | 590 – Consecration of Pope Gregory I (Gregory the Great). |
| 100041 | September 3 | Event | 673 – King Wamba of the Visigoths puts down a revolt by Hilderic, governor of Nîmes (France) and rival for the throne. |
| 100042 | September 3 | Event | 863 – Major Byzantine victory at the Battle of Lalakaon against an Arab raid. |
| 100043 | September 3 | Event | 1189 – Richard I of England (a.k.a. Richard "the Lionheart") is crowned at Westminster. |
| 100044 | September 3 | Event | 1260 – The Mamluks defeat the Mongols at the Battle of Ain Jalut in Palestine, marking their first decisive defeat and the point of maximum expansion of the Mongol Empire. |
| 100045 | September 3 | Event | 1650 – Third English Civil War: In the Battle of Dunbar, English Parliamentarian forces led by Oliver Cromwell defeat an army loyal to King Charles II of England and led by David Leslie, Lord Newark. |
| 100046 | September 3 | Event | 1651 – Third English Civil War: Battle of Worcester: Charles II of England is defeated in the last main battle of the war. |
| 100047 | September 3 | Event | 1658 – Richard Cromwell becomes Lord Protector of England. |
| 100048 | September 3 | Event | 1666 – The Royal Exchange burns down in the Great Fire of London. |
| 100049 | September 3 | Event | 1777 – American Revolutionary War: During the Battle of Cooch's Bridge, the Flag of the United States is flown in battle for the first time. |
| 100050 | September 3 | Event | 1783 – American Revolutionary War: The war ends with the signing of the Treaty of Paris by the United States and the Kingdom of Great Britain. |