Lamballe was the capital of the territory of the Counts of Penthièvre, who in 1569 were made dukes.
La Noue, the famous Huguenot leader, was mortally wounded in 1591 in the siege of the castle, which was dismantled in 1626 by Richelieu. The last Duke of Penthièvre granted his son Louis the title Prince of Lamballe. The Prince de Lamballe married Marie Therese de Savoie-Carignan and she took the title Princesse de Lamballe. The Princesse lived with her father-in-law after the early death of her husband. She was a close friend of Queen Marie Antoinette and one of the most famous victims of the French Revolution.