. Condate, at the confluence of the small rivers Ille and Vilaine in east-central Armorica, or Brittany, was the chief city of the Redones. It was fortified in the late 3rd century; an important abbey commemorated the cult of an early bishop, St. Mélaine (d. ca. 530). Frankish influence was strong, and with Nantes, Rennes formed part of the March of Brittany. In 831, however, Emperor Louis the Pious, unable to defeat the Bretons by force, appointed Nominoe missus of both the Celtic and Frankish parts of Brittany, and Rennes came under Breton political control. Factional disputes and Viking invasions allowed a new comital dynasty to emerge; ties with royal France remained strong. The 10th and 11th centuries witnessed an intense rivalry with the counts of Nantes for the ducal title, which Conan I of Rennes (d. 992) obtained. A family quarrel allowed Eudo, brother of Alain III (r. 1008–40), to seize Rennes after his death. From 1084, Alain Fergent (r. 1084–1113) reunited it with the rest of the ducal domain. With Nantes and Vannes, Rennes remained a center of ducal administration.
The court of the seneschal at Rennes received appeals from other Breton sénéchaussées, with the exception of Nantes. The city, politically and strategically important, was frequently attacked. Its Roman walls, which had enclosed 22 acres, were strengthened by a ducal castle after the late 10th century.
Henry II of England took the town in 1182 and destroyed the castle. During the Breton civil war (1341–64), Rennes was held for Charles de Blois and Jeanne de Penthièvre; it withstood a nine-month siege by the English (1356–57). But the need to defend new suburbs and a total population of around 14,000, living in nine parishes, led between 1421 and 1476 to the construction of two further enceintes. Some 155 acres were eventually enclosed, including the abbey of Saint-Georges, a ducal foundation (ca. 1030) for Benedictine nuns, and low-lying quarters south of the Vilaine, where small craft industries, notably textile and leatherworking, had developed. The defenses were tested for the last time by a French siege in 1491, before Duchess Anne married Charles VIII and delivered Rennes, and Brittany, into royal hands. Among the distinguished bishops of Rennes may be noted the poet and reformer Marbode (r. 1096–1120) and Étienne de Fougères (r. 1168–78), author and servant of Henry II of England. St. Yves Helory (d. 1303) was briefly the bishop’s official. A Franciscan convent was established ca. 1238; the Dominicans arrived in 1368 and the Carmelites in 1448. Printing was introduced in 1483. Medieval Rennes was almost totally destroyed in a great fire in 1720. The church of Saint-Mélaine has some Romanesque portions but was poorly rebuilt in the 14th, 15th, and 17th centuries.
