Conan II of Rennes (died 1066) was Duke of Brittany, from 1040 to his death. He was son of Duke Alan III and Bertha of Blois. Brittany was ruled by his uncle Eudes of Brittany in his first twenty years as Duke. Conan faced numerous threats to the duchy of Brittany, including revolts from his nobles and attacks by William, Duke of Normandy, afterwards King of England.
Before his invasion of Anglo-Saxon England, William of Normandy sent word to the surrounding counties, including Brittany, asking that they abstain from any attacks on his duchy, on the grounds that his mission bore the papal banner. Conan promptly informed the duke that he would definitely take the opportunity to invade the latter's duchy. Not long after, Conan was found dead after donning poisoned riding gloves. Duke William was suspected (Howarth, 1066: The Year of Conquest). Conan was succeeded by his brother-in-law. See also: Dukes of Brittany family tree
| Preceded by Alan III |
Duke of Brittany 1040–1066 |
Succeeded by Hoel II |
