Conan I (? June 27, 992) nicknamed Le Tort was the Duke of Brittany from 990 to his death. He was the son of Judicael Berengar and Gerberga, and succeeded his father as Count of Rennes in 970.
He assumed the title of Duke of Brittany in the spring of 990 following his attack on Nantes and the subsequent death of Count Alan. As duke his rule succeeded the Regency that governed Brittany during the life of Drogo and the fractured rule of Brittany after Drogo's death by his brothers Hoël and Guerech . The fractured rule over Brittany resulted in a short vacancy in the title Duke of Brittany; Conan I had to ally himself with the Count of Blois in order to defeat Judicael Berengar before he could assume the title of Duke.
Mont Saint-Michel, endowed by Conan I, and his final resting place
In a charter dated 28 July 990, Conan gave the lands of Villamée, Lillele and Passille to Mont Saint-Michel, all of which later became part of the seigneury of Fougères.
Conan married Ermengarde-Gerberga of Anjou, in 973, daughter of Geoffrey I, Count of Anjou and Adele of Vermandois.
Conan's alliance with the Count of Blois had helped him defeat Judicael Berengar, he later needed to "rid himself of influence from Blois, [which he accomplished by signing] a pact with Richard I of Normandy; [this pact] established firm Breton-Norman links for the first time." Richard I had married the daughter of Hugh I the Great, and after this marriage had re-asserted his father's claim as Overlord of the Breton duchy. Conan I's pact with him strengthened that assertion but the historical documentation for that Overlordship claim remains doubtful because it largely appears only in the less than authoritative writings of Dudo of Saint-Quentin.
Conan died fighting his brother-in-law Fulk Nerra, Count of Anjou at the Battle of Conquereuil on 27 June 992. Conan is buried at Mont Saint-Michel Abbey (wikipedia)