Joan, Duchess of Brittany

Joan of Penthièvre
Tomb of Jeanne de Penthièvre, Duchess of Brittany
Duchess of Brittany
Reign30 April 1341 –1365
(disputed suo jure)
1365–10 September 1384 (titular)
PredecessorJohn III
SuccessorJohn IV
Born1319
Died10 September 1384 (aged 65)
Guingamp
Burial
church of the Friars Minor of Guingamp.
SpouseCharles I, Duke of Brittany
IssueJohn I, Count of Penthièvre
Guy
Henry
Marie, Lady of Guise
Marguerite, Countess of Angoulême
HouseDreux
FatherGuy de Penthièvre
MotherJeanne d'Avaugour
ReligionRoman Catholicism

Joan of Penthièvre (French: Jeanne de Penthièvre; c. 1319 – 10 September 1384) reigned as Duchess of Brittany together with her husband, Charles of Blois, between 1341 and 1364. Her ducal claims were contested by the House of Montfort, which prevailed only after an extensive civil war, the War of the Breton Succession. After the war, Joan remained titular Duchess of Brittany to her death. She was Countess of Penthièvre in her own right throughout her life.