War of the Breton Succession

War of the Breton Succession
	Part of the Hundred Years' War
	; Battle of Auray
Date	1341 – 12 April 1365
Location	Brittany
Result	Treaty of Guérande; Montfort military victory; French strategic and political victory;
Belligerents
House of Dreux-Montfort; Kingdom of England;	House of Châtillon-Blois; Kingdom of France; Kingdom of Castile;
Commanders and leaders
John of Montfort #; Joanna of Flanders; John IV of Brittany; Sir Thomas Dagworth;	Charles of Blois †; Joan of Penthièvre

The War of the Breton Succession (French: guerre de Succession de Bretagne, Breton: Brezel hêrezh dugelezh Breizh) was a conflict between the Counts of Blois and the Montforts of Brittany for control of the Sovereign Duchy of Brittany, then a fief of the Kingdom of France. It was fought between 1341 and 12 April 1365.^[1] It is also known as the War of the Two Jeannes (French: guerre des deux Jeannes) due to the involvement of two rival duchesses of that name (Jeanne (Joanna) of Flanders and Jeanne de Penthièvre).^[2]

The war formed an integral part of the early Hundred Years' War due to the proxy involvement of the French and English monarchs in the conflict; the French supported the Blois (female heir) whilst the English backed the Montforts (male heir). The rival kings supported the Sovereign Duke of the principle opposite to their own claims to the French throne—the Plantagenet having claimed it by female succession, and the Valois by male succession. Montfort was ultimately successful following the Battle of Auray in 1364 but, in a surprising turn of events, pledged his loyalty to the King of France and not to the Plantagenet king of England who had supported him.

^ ^a ^b Ronald H. Fritze; William Baxter Robison (2002). Historical Dictionary of Late Medieval England, 1272–1485. Greenwood Publishing Group. p. 231. ISBN 978-0-313-29124-1.
^ Jenkins, Claude (13 May 1929). "Mediaeval European History, A.D. 455–1453". E. Benn – via Google Books.; Tanner, Heather J. (9 January 2019). Medieval Elite Women and the Exercise of Power, 1100–1400: Moving beyond the Exceptionalist Debate. Springer. ISBN 9783030013462 – via Google Books.; Graham-Goering, Erika (31 March 2020). Princely Power in Late Medieval France: Jeanne de Penthièvre and the War for Brittany. Cambridge University Press. ISBN 9781108805544 – via Google Books.

[FritzeRobison2002-1] Ronald H. Fritze; William Baxter Robison (2002). Historical Dictionary of Late Medieval England, 1272–1485. Greenwood Publishing Group. p. 231. ISBN 978-0-313-29124-1.

[2] Jenkins, Claude (13 May 1929). "Mediaeval European History, A.D. 455–1453". E. Benn – via Google Books.; Tanner, Heather J. (9 January 2019). Medieval Elite Women and the Exercise of Power, 1100–1400: Moving beyond the Exceptionalist Debate. Springer. ISBN 9783030013462 – via Google Books.; Graham-Goering, Erika (31 March 2020). Princely Power in Late Medieval France: Jeanne de Penthièvre and the War for Brittany. Cambridge University Press. ISBN 9781108805544 – via Google Books.

[1]

[2]