Wikipedia:Selected anniversaries/September 14
- 786: Harun al-Rashid became the Abbasid caliph upon the death of his brother al-Hadi.
- 1752: The British Empire adopted the Gregorian calendar, skipping eleven days (September 2 was followed directly by September 14).
- 1812: Napoleon's invasion of Russia: Napoleon and his Grande Armée captured Moscow, only to find the city deserted and burning.
- 1901: Theodore Roosevelt became President of the United States upon the assassination of William McKinley.
- 1959: The Soviet spacecraft Luna 2 (pictured) crashed onto and became the first man-made object to reach the Moon.
- 1960: The Organization of the Petroleum Exporting Countries (OPEC) was founded by Iran, Iraq, Kuwait, Saudi Arabia and Venezuela.
Recent days: September 13 – September 12 – September 11
More anniversaries: