The House of Rennes was a Breton dynasty that ruled Brittany from 990 to 1072, with Conan I of Brittany as the first Rennes duke of Brittany. The dynasty ruled for almost a hundred years, and the dynasty was terminated with the death of Conan II of Brittany in 1066; his sister Hawise of Brittany married Hoel II of Brittany, whose overthrow in 1072 by Alan IV of Brittany and the House of Cornouaille ended the House of Rennes' rule.