Counts and dukes of Penthièvre

Alan III, Duke of Brittany, gave it to his brother Eudes in 1035, and his descendants formed a cadet branch of the ducal house.

The Duke of Brittany, Pierre Mauclerc, founder of the Breton House of Dreux, gave it as dowry to his daughter, Yolande, on her marriage in 1238 to Hugh XI of Lusignan, Count of La Marche.

[1] After the Breton War of Succession the title was dispossessed twice by the reigning Dukes of Brittany, once by John V and another time by Francis II.

In 1337 Joan the Lame, Duchess of Brittany, brought Penthièvre to her husband, Charles de Châtillon, Count of Blois.

When John went into exile in England in 1373, Charles V of France named his brother Louis, Duke of Anjou lieutenant-general of Brittany.

When Francis died in 1488, Nicole's eldest son Jean III de Brosse (d. 1502) asserted his family's claim to the duchy against those of Anne, Duchess of Brittany, who ultimately ascended to the title.

He allied with Spain and defeated Henry IV of France's attempts to subjugate Brittany until 20 March 1598 when Mercœur was forced to surrender and subsequently went in exile to Hungary.