The Counts of Nantes were originally the Frankish rulers of the Nantais under the Carolingians and eventually a capital city of the Duchy of Brittany. Their county served as a march against the Bretons of the Vannetais. Carologinian rulers would sometimes attack Brittany through the region of the Vannetais, making Nantes a strategic asset. In the mid-ninth century, the county finally fell to the Bretons and the title became a subsidiary title of the Breton rulers. The control of the title by the Breton Dukes figured prominently in the history of the Duchy. The title Count of Nantes was given to Hoel, a disinherited son of a Duke. He lost the Countship due to a popular uprising. That uprising presented an opportunity for King Henry II of England to attack the Breton Duke. In the treaty ending their conflicts, the Breton Duke awarded the Countship of Nantes to Henry II.
---- – 778 Roland, as prefect of the Breton March - subject of the Chanson de Roland
786 – 818 Guy, as prefect of the Breton March, successor to Roland
818 – 831 Lambert I - exiled by Charlemagne and replaced by Ricwin.
831 – 841 Ricwin -a comes of Charlemange, and fidelis of Louis the Pious, he opposed Nominoe in the founding of Redon Abbey
841 – 843 Renaud
843 – 846 Lambert II
846 – 849 Amaury, imposed by Charles the Bald in opposition to Lambert II
849 – 851 Lambert II (restored)
852 – 860 Salomon de Bretagne
861 – 866 Robert the Strong, also Count of Anjou
866 – --- Hugh of the Breton March
--- – --- Henry of the Breton March
--- – --- Odo, the future Odo, King of West Francia, as the Marquis of Neustria
886 – 896 Berengar II of Neustria as Margrave of the Breton March, later also Count of Rennes
896 – 911
911 – --- Robert, the future Robert I of France as the Marquis of Neustria
Alan I, King of Brittany ruled Nantes as King of Brittany until his death in 907.
907 - c 914 - vacant
914 - 919 - Rognvaldr as leader of the Loire Fleet of Norway lands in Nantes; Robert of Neustria continues conflict with invading Vikings
919 - Robert of Neustria cedes Nantes to Rognvaldr
? - 936 - Incon, Viking leader after the death of Rognvaldr
936 - 938 - Alan Barbetorte returns to Brittany from England and engages the Vikings
938 – 952 Alan I Barbetorte
952 – 960 Drogo
960 – 981 Hoël I
981 – c.988 Guerech
990 – 992 Conan I, Count of Nantes by conquest
992 – 1004 Judicael
1004 – 1038 : Budic
1038 – 1051 : Matthew I
1051 – 1063 : Judith (with Alain Canhiart)
1054 – 1084 : Hoël II
1084 – 1103 : Matthew II
1103 – 1119 Alan II
1119 – 1148 Conan II
1148– 1156 Hoël III
1156 – 1158 Geoffrey I FitzEmpress, younger brother of Henry II of England
1158 Conan III, seized the County and Nantes before returning it to Henry of England
1158 – 1185 Henry II of England, gained the county under his treaty with the Duke of Brittany
1185 – 1186 Geoffrey II
1185 – 1201 Constance
1196 – 1203 Arthur
The County of Nantes was merged permanently into the Ducal crown of Brittany, and subsequently the crown of France, through Constance's descendants.
