Revised 29/04/2020



The Dukedom was not recognised as such until the 13th Century, but some of the earlier Counts of Brittany styled themselves Dukes.


[RENN281] Ridoredh/Riwallon (born c.805, son of Erispoe I, see ALAIN), Count of Nantes. He died 857.

[RENN291] Matudoi (born c.828), Earl of Poher. He died 868.

[RENN301] Alain I le grand (born c.854), Count of Vannes & Nantes, Count of Porhoet, DUKE ALAIN I jointly ruled Brittany (by 876) with Gurwent's son, Judicael, and then solely after Judicael was killed fighting the Vikings (888). Alain married [CORN302] Oreguen (daughter of Alfrond ap Justin, see HOUSE OF CORNOUAILLE below, and died 907.

[RENN312] --- (daughter of Alain I) married [NANT311] Count Matuedo (see NANTES COUNTY).

[VANN311] Rudalt (son of Alain I), Comte de Vannes, is described under VANNES COUNTY.

[RENN311] Paskwitan II ([born c.875], son of Alain I) married [BABE262] --- de Rennes (daughter of Count Berengar II, see BABENBURG), and thereby became Count of Rennes.

[RENN321] Juhael [Judicael] Berengar (born c.900), Count of Rennes & Bretagne, married Gerberge. He died 970.

[VITR311] Martin de Rennes (born c.935, son of Juhael Berengar) is described under VITRE.

[RENN331] Conan I le tours, le tort [=the crooked], (born c.927, son of Juhael Berengar, "Conani filii Juhelli Berengarii").

Conan also claimed descent from [ALAI291] Erispoe, Ruler of Bretagne, see BRETAGNE (ALAIN) KINGDOM).

Conan was Count of Rennes, and 6th Count of Brittany (987-92). He married (c.973) [ANJO313] Ermengarde (daughter of Count Geoffrey, see ANJOU COUNTY), and was killed in battle (26th June or 4th July 992).

[RENN342] Judith (eldest daughter of Conan I) married (at Mont, Saint-Michel, 1000) [NORM311] DUKE RICHARD II (see NORMANDY DUKEDOM).

[PORH321] Judhael de Porhoet (born c.984, son of Conan I) is dealt with under PORHOET.

[RENN341] Geoffrey I de Brittany (born c.980, son of Conan I), was Count of Rennes, and 7th Count of Brittany (992-1008). He married [NORM314] Hawise (daughter of DUKE RICHARD I, see NORMANDY DUKEDOM), and died November 1008. Hawise died 21st February 1034.

[PENT359] Eudes aka Odo (born c.999, son of [RENN341] Geoffrey I), Count of Penthievre, married [CORN362] Orguen/Agnes (daughter of [CORN351] Count Alain III of Cornouaille, see below under HOUSE OF CORNOUAILLE). He also had eight children by various mistresses, including it is believed a daughter of Thorfinn. He died 7th January 1079.

[PENT362] Alan Rufus (born c.1040, 2nd son of Eudes & Orguen}, companion of William the Conqueror, late Lord of Richemont (Normandy). Around 1069 Alan  received the Honour of Richmond in north Yorkshire  Here Alan founded the town of Hindrelag (later known as Richmond), and built a stone castle. The first Constable of the castle was Enisant Musard (see MUSARD). The spectacular keep was probably added to the castle a century later by Conan IV, 2nd Earl of Richmond (see RICHMOND EARLDOM). Alan died 1089 and his estates passed to his two surviving brothers, Alan and Stephen (see below).

[BARF311] Bardolf (born c.1050, son of Eudes & a mistress) is described under BARDOLF.

[RICH351] Stephen aka Etienne de Treguier (born c.1060, youngest son of Eudes & Orguen), Count of Penthievre, is described under RICHMOND EARLDOM.

[PENT361] Sir William de Ramsey (born c.1040, said to be son of Eudes & Orguen) married Lesceline.

[PENT372] Emme ([born c.1060], daughter of William) possibly married [BRUC431] Adam de Brus (see ANNANDALE LORDSHIP).

[PENT365] Matilda of Brittany (born c.1049, daughter of Odo, Count of Penthievre & [CORN362] Agnes de Cornouaille) married [DEIN341] Walter I d'Eyncourt (born1043, in Normandy),.see DEINCOURT)

[RENN352] Emma (daughter of Geoffrey I) married Vicomte Ivo de Cotentin (see FITZNIGEL).

[RENN351] Alan III (born c.997, son of Geoffrey I) was 8th Count of Brittany (1008-40). He married [BLOI333] Bertha (daughter of Count Eudes II, see CHAMPAGNE COUNTY). Alan was poisoned at Vimontier (October 1040), and afterwards Bertha married 2. (after 1046) Count Hugh IV of Maine. She died 1084.

[RENN362] Hawise (daughter of Alan III, and sister of Conan, the 9th Count) married [CORN361] Count Hoel of Cornouaille, who through this marriage afterwards became 10th Count of Brittany (1066, see HOUSE OF CORNOUAILLE below).

(A region in present-day Brittany)

[CORN281] Justin (born c.790, ap [URBI271] Constantine ap Judon (see BRETAGNE (URBIEN) KINGDOM).

[CORN291] Alfrond (born c.830, ap Justin).

[CORN302] Oreguen (born 860, daughter of Alfrond) married [ALAI301] DUKE ALAIN I see HOUSE OF RENNES above.

[CORN301] Ulfret Alesrudon (born c.870, son of Alfrond), Prince of Cornouaille.

[CORN311] Diles Heirguor Ehebre (born c.890), Prince of Cornouaille, married his third-cousin [URBI312] Alava de Cornouaille (see BRETAGNE (URBIEN) KINGDOM). He died c.946-52.

[CORN321] Budic Bud Berhuc (born c.910), Prince of Cornouaille.

[CORN331] Budic IV (born c.940), Castellan, Count of Cornouaille.

[CORN341] Benedict (born c.957) aka Budik V, Prince of Cornouaille, Count of Cornouaille, Bishop, married Guinodeon de Porhoet.

[CORN351] Alain III caignart (born 975), Count of Cornouaille, married (c.1006) [NANT352] Judith (born c.988, daughter of Count Judicael, see NANTES). He died (age 51) in 1026.

[CORN362] Orguen/Agnes de Cornouaille (born c.1005, daughter of Alain) married [PENT353] Count Eudes I (see HOUSE OF RENNES above).

[CORN363] Alarun de Cornouaille (possibly daughter of Alain) married [PORH331] Vicomte Guethenoc (born c.1040), see PORHOET).

[CORN361] Hoel (son of Alain), Count of Cornouaille, married [RENN362] Hawise (see HOUSE OF RENNES above). He was 10th COUNT OF BRITTANY (1066-84). Hawise died 19th August 1072, and Hoel died 13th April 1084.

[CORN371] Alan IV fergant [=red hair] (born c.1067, son of Hoel & Hawise) was 11th Count of Brittany (1084-1112). He married 1. (at Caen, 1086) Constance (daughter of William the Conqueror); then 2. (c.1093) [GATI342] Ermengarde (see ANJOU (HOUSE OF GATINAIS) COUNTY), who had previously married 1. (1089) DUKE WILLIAM IX OF AQUITAINE, divorced 1090. In the Domesday Survey, Alan held, of King William I, land in Cambridgeshire, Dorset, Essex, Hampshire, Hertfordshire, Lincolnshire, Norfolk, Northamptonshire, Nottinghamshire, Suffolk and Yorkshire. Alan abdicated his Countdom (1112), and died October 13th 1119. Ermengarde died at Jerusalem (1st June 1146).

[CORN382] Hawise de Brittany (daughter of Alan IV & Ermengarde) married 1. (1105) Baudouin VII, Count of Flanders, afterwards separated for consanguinity; 2. [PORH361] Vicomte Geoffrey, see PORHOET).

[CORN381] Conan III the fat (born 1089, son of Alan IV & Ermengarde) married [NORK353] Maud (illegitimate daughter of King Henry I, see NORMAN KINGS). He was 12th Count of Brittany (1112-48), and died 1148.

[CORN399] Bertha (daughter & heiress of Conan III), heiress of Bretagne, Nantes, Cornouaille and Leon, married 1. [RICH361] Earl Alan III (see HOUSE OF RICHMOND below); then 2. (c.1148) [PORH371] Vicomte Eudon (see PORHOET).


(see RICHMOND EARLDOM for full details)

[RICH361] Alan III, 1st Earl of Richmond, (son of [RICH351] Stephen, see RICHMOND EARLDOM) married [CORN399] Berthe of Brittany (see above). Alan died 15th September 1146, and afterwards Bertha married 2. (c.1148) [PORH371] Eudon, Vicomte de Porhoet, who thus became 13th Count of Brittany, see PORHOET.

[RICH371] Conan IV, 2nd Earl of Richmond (son of Alan III & Bertha) married (1160) [CANM469] Margaret (daughter of Earl Henry, see HUNTINGDON (DUNKELD) EARLDOM). He was 2nd Earl of Richmond (1146-66) and 14th Count of Brittany (1156-66), but he was forced by King Henry II to resign both titles (1166) in favour of his daughter Constance, and then betrothing her to his son Prince Geoffrey II. Constance died February 1171. Afterwards Margaret married 2. (1175) [HERE451] Humphrey de Bohun (see HEREFORD (BOHUN) EARLDOM).

[RICH383] Constance (born 1163, only daughter & heir of Conan IV), Countess of Richmond and DUCHESS OF BRITTANY, married 1. (July 1181) Prince Geoffrey II (born 1158, son of King Henry II), killed at Paris in a tournament, August 1186; then 2. (February 1188) Ranulph, 7th Earl of Chester, dissolved 1199 after his desertion; then 3. (at Angers, 1199) [THOU362] Guy de Thouars (see below).


(see THOUARS for full details)

[THOU362] Guy de Thouars (son of [THOU352] William, see THOUARS), Vicomte de Thouars, married (at Angers, 1199) [RICH383] Constance, Countess of Richmond and DUCHESS OF BRITTANY (see above). Constance died at Nantes (September 1201), and Guy died 1213.

[THOU372] Alix (daughter of Guy), 17th DUCHESS or Comtesse OF BRITTANY (1203-13), married (1213) [DREU411] DUKE PETER DE DREUX (see below).

[THOU373] Catherine (daughter of Guy) married  [VITR391] Andre III, Baron of Vitry, see VITRE.


(see DREUX COUNTY for full details)

[DREU411] Peter de Dreux mauclerc (2nd son of [DREU401] Count Robert III, see DREUX COUNTY), was Count of Richmond, Seigneur de Fere, Pontarcy, Brie-Comte-Robert, Chailly and Longjumeau.