Ancient Diocese of Dol

The Breton and French Catholic diocese of Dol, situated in the northern part of the department of Ille-et-Vilaine, 6 km (3.8 mi) from the English Channel coast and 22 km (14 mi) southeast of Saint-Malo, existed from 848 until the French Revolution. It was suppressed by the Concordat of 1801.

The seat of the bishop was the cathedral of Saint Samson. Its scattered territory (deriving from the holdings of the Celtic monastery, and including an enclave at the mouth of the Seine) was shared mainly by the Diocese of Rennes and the Diocese of Saint-Brieuc.

The Life of St. Samson, which cannot be of earlier date than the seventh century, mentions the foundation of the monastery of Dol by Samson of Dol. Georges Goyau speculates that Samson was most likely already a bishop when he arrived in Armorica from Great Britain, but finds no evidence in the Life that Samson founded the See of Dol or became its first bishop.

In the twelfth century, to support its claim against the Metropolitan of Tours, the Church of Dol produced the names of a long list of archbishops: St. Samson, St. Magloire, St. Budoc, St. Génevée, St. Restoald, St. Armel, St. Jumael, St. Turian. Louis Duchesne discounted and doubted this list. He was of the opinion that the abbey of Dol may have had at its head from time to time abbots with episcopal jurisdiction, but that Dol was not the seat of a diocese.

Under Charlemagne and Louis the Pious, the Vicariate of Dol and the monastery of St. Méen were still included in the Diocese of Aleth; so that the first Bishop of Dol was Festianus (Festgen) mentioned for the first time between 851 and 857, and installed by King Nomenoë.

Among the bishops of Dol are:

There was a struggle from the ninth to the eleventh century to free the Church of Brittany from the Metropolitan of Tours. From a comparison made by Duchesne between the Life of St. Conwoïon, the Indiculus de episcoporum Britonum depositione, and an almost completely restored letter of Pope Leo IV, it would appear that shortly before 850, Nomenoë wishing to be anointed king, and finding opposition among the prelates of Brittany, sought to get rid of them by charging them with simony. Their only real fault was perhaps that they demanded eulogia from their priests when the latter came to synods. After listening to a deputation of Breton bishops and to St. Conwoïon, founder of the Abbey of St-Sauveur at Redon, who had been sent to Rome by Nomenoë, Leo IV declared that the charge of simony must be adjudicated by a competent tribunal of twelve bishops, and must be attested by seventy-two witnesses, thereby disputing Nomenoë's claim to a right to depose bishops. But Nomenoë did depose, and in a brutal manner, the four bishops of Vannes, Aleth, Quimper, and St. Pol de Léon, and made seven dioceses out of their four. One of the new dioceses had its seat in the abbey of Dol and became straightway an archdiocese. The other two dioceses were established in the monasteries of St. Brieuc and Tréguier (Pabu-Tutual).

In Autumn 849, the bishops of the four provinces of Tours, Sens, Reims, and Rouen, wrote a letter of reprimand to Nomenoë and threatened him with excommunication. He paid no heed to them, and died 7 March 851.