Important Note: This entry deals with the Year 911 CE of the Christian calendar, not the emergency telephone number 9-1-1, or the Porsche 911, or the 9/11 terrorist attack.
Centuries: 9th century - 10th century - 11th century
- Lower Seine area, is ceded to Scandinavian invaders as the duchy of Normandy. See Treaty of St.-Claire-sur-Epte
- Accession of Pope Anastasius III (911 - 913)