Conan III, Duke of Brittany

Conan III, also known as Conan of Cornouaille and Conan the Fat (Breton: Konan III a Vreizh, and Konan Kerne; c. 1093–1096 – September 17, 1148) was duke of Brittany, from 1112 to his death. He was the son of Duke Alan IV and Ermengarde of Anjou.[1]

Conan III allied himself with Stephen of England in the Anarchy, Stephen's war against the dispossessed Empress Matilda.[a][b]


He married Maud, an illegitimate daughter of King Henry I of England before 1113.[2] Conan and Maud had three children that are known:

  • Hoel (1116 - 1156) – disinherited from the Ducal crown; Count of Nantes;[3]
  • Bertha (1114 - after 1155) – married Alan of Penthièvre;[3][c] upon Alan's death in 1146, she returned to Brittany;
  • Constance (1120 - 1148) – married Sir Geoffroy II, Sire de Mayenne, son of Juhel II, Seigneur de Mayenne.


On his death-bed in 1148, Conan III disinherited Hoel from succession to the Duchy, stating that he was illegitimate and no son of his. By this surprise move Bertha became his heiress and successor. However, Hoel was to retain the County of Nantes.[4]


  1. ^ Stephen created Conan's son-in-law Alan 1st Earl of Richmond. Alan rode by the side of Stephen in the Battle of Lincoln.
  2. ^ The Earldom of Richmond was inherited by Alan's son, and Conan III's grandson Conan IV. It would remain in the Ducal house of Brittany for some time.
  3. ^ King Stephen of England created Alan 1st Earl of Richmond and 1st Earl of Cornwall


  1. ^ Everard 2004, p. 10.
  2. ^ Bryan 2016, p. 173.
  3. ^ a b Warren 1977, p. 75.
  4. ^ Everard 2004, p. 32.


  • Bryan, Elizabeth J. (2016). "Matthew Parker and the Middle English Prose Brut". In Rajsic, Jaclyn; Kooper, Erik; Hoche, Dominique (eds.). The Prose Brut and Other Late Medieval Chronicles. York Medieval Press.
  • Everard, J. A. (2004). Brittany and the Angevins: Province and Empire 1158–1203. Cambridge University Press.
  • Warren, Wilfred Lewis (1977). Henry II. Yale University Press.

See alsoEdit

Conan III, Duke of Brittany
House of Cornouaille
Born: c.1053 Died: 17 September 1148
Regnal titles
Preceded by Duke of Brittany
Succeeded by
Count of Nantes and Rennes
Succeeded by