1291 CE
A year that saw the fall of Acre and the end of the Crusader states in the Holy Land, the founding of the Swiss Confederation, and the continued expansion of the Mamluk Sultanate.
Conflict & Security
- The Mamluk Sultan al-Ashraf Khalil besieged and captured the city of Acre on May 18, the last major Crusader stronghold in the Holy Land, after a siege lasting six weeks.
- The fall of Acre was accompanied by fierce fighting, with the defenders including Templar, Hospitaller, and Teutonic Knights making a desperate last stand before the city was overrun and destroyed.
- The remaining Crusader outposts along the Levantine coast, including Tyre, Sidon, and Beirut, were abandoned or fell to the Mamluks in the weeks following the fall of Acre.
- The loss of Acre ended nearly two centuries of continuous Crusader presence in the Holy Land, marking the definitive failure of the Crusading movement to maintain a permanent Christian foothold in the Middle East.
Geopolitics & Diplomacy
- The three Swiss forest cantons of Uri, Schwyz, and Unterwalden formed the Eternal Alliance on August 1, traditionally regarded as the founding of the Swiss Confederation.
Climate & Environment
- Atmospheric carbon dioxide concentration was approximately 275 parts per million, as later confirmed by ice core analysis.
Culture & Society
- The estimated world population was approximately 390 million.