| 81391 | July 17 | Holiday and observance | King's Birthday (Lesotho) |
| 81392 | July 17 | Holiday and observance | World Day for International Justice (International) |
| 81393 | July 18 | Event | 390 BC – Roman-Gaulish Wars: Battle of the Allia: A Roman army is defeated by raiding Gauls, leading to the subsequent sacking of Rome. |
| 81394 | July 18 | Event | 64 – The Great Fire of Rome causes widespread devastation and rages on for six days, destroying half of the city. |
| 81395 | July 18 | Event | 362 – Roman–Persian Wars: Emperor Julian arrives at Antioch with a Roman expeditionary force (60,000 men) and stays there for nine months to launch a campaign against the Persian Empire. |
| 81396 | July 18 | Event | 645 – Chinese forces under general Li Shiji besiege the strategic fortress city of Anshi (Liaoning) during the Goguryeo–Tang War. |
| 81397 | July 18 | Event | 1290 – King Edward I of England issues the Edict of Expulsion, banishing all Jews (numbering about 16,000) from England this was Tisha B'Av on the Hebrew calendar, a day that commemorates many Jewish calamities. |
| 81398 | July 18 | Event | 1334 – The bishop of Florence blesses the first foundation stone for the new campanile (bell tower) of the Florence Cathedral, designed by the artist Giotto di Bondone. |
| 81399 | July 18 | Event | 1342 – Mu'izz al-Din Husayn defeats the Sarbadars in the Battle of Zava. |
| 81400 | July 18 | Event | 1389 – France and England agree to the Truce of Leulinghem, inaugurating a 13-year peace, the longest period of sustained peace during the Hundred Years' War. |
| 81401 | July 18 | Event | 1391 – Tokhtamysh–Timur war: Battle of the Kondurcha River: Timur defeats Tokhtamysh of the Golden Horde in present-day southeast Russia. |
| 81402 | July 18 | Event | 1555 – The College of Arms is reincorporated by Royal charter signed by Queen Mary I of England and King Philip II of Spain. |
| 81403 | July 18 | Event | 1812 – The Treaties of Orebro ends both the Anglo-Russian and Anglo-Swedish Wars. |
| 81404 | July 18 | Event | 1841 – Coronation of Emperor Pedro II of Brazil. |
| 81405 | July 18 | Event | 1857 – Louis Faidherbe, French governor of Senegal, arrives to relieve French forces at Kayes, effectively ending El Hajj Umar Tall's war against the French. |
| 81406 | July 18 | Event | 1862 – First ascent of Dent Blanche, one of the highest summits in the Alps. |
| 81407 | July 18 | Event | 1863 – American Civil War: Second Battle of Fort Wagner: One of the first formal African American military units, the 54th Massachusetts Volunteer Infantry, supported by several white regiments, attempts an unsuccessful assault on Confederate-held Battery |
| 81408 | July 18 | Event | 1870 – The First Vatican Council decrees the dogma of papal infallibility. |
| 81409 | July 18 | Event | 1914 – The U.S. Congress forms the Aviation Section, U.S. Signal Corps, giving official status to aircraft within the U.S. Army for the first time. |
| 81410 | July 18 | Event | 1925 – Adolf Hitler publishes his personal manifesto Mein Kampf. |
| 81411 | July 18 | Event | 1936 – An army uprising in Spanish Morocco starts Spanish Civil War. |
| 81412 | July 18 | Event | 1942 – World War II: The Germans test fly the Messerschmitt Me 262 using its jet engines for the first time. |
| 81413 | July 18 | Event | 1944 – World War II: Hideki Tōjō resigns as Prime Minister of Japan because of numerous setbacks in the war effort. |
| 81414 | July 18 | Event | 1966 – Human spaceflight: Gemini 10 is launched from Cape Kennedy on a 70-hour mission that includes docking with an orbiting Agena target vehicle. |
| 81415 | July 18 | Event | 1966 – Australian children's television series Play School airs for the first time, going on to become the longest-running children's show in Australia, and the second longest running children's show in the world |
| 81416 | July 18 | Event | 1968 – Intel is founded in Mountain View, California. |
| 81417 | July 18 | Event | 1969 – After a party on Chappaquiddick Island, Senator Ted Kennedy from Massachusetts drives his car off a bridge and his passenger, Mary Jo Kopechne, dies. |
| 81418 | July 18 | Event | 1976 – Nadia Comăneci becomes the first person in Olympic Games history to score a perfect 10 in gymnastics at the 1976 Summer Olympics. |
| 81419 | July 18 | Event | 1982 – Two hundred sixty-eight campesinos ("peasants" or "country people") are slain in the Plan de Sánchez massacre in Ríos Montt's Guatemala. |
| 81420 | July 18 | Event | 1984 – McDonald's massacre in San Ysidro, California: In a fast-food restaurant, James Oliver Huberty opens fire, killing 21 people and injuring 19 others before being shot dead by police. |