Britannica
Sources used in this answer
When did the ruler of Brittany begin using the title of duke?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Brittany
The old walled city of Saint-Malo, Brittany région, France.
The ruler of Brittany began using the title of duke in the 10th century. During this period, the rulers established their capital at Rennes. While these rulers were recognized as dukes, they often struggled to consolidate power over their vassals and faced significant threats from neighboring powers, such as the dukes of Normandy.12