Diocese of Dol
The diocese of Dol was established in the 6th century . First bishop was Samson . Between 848 and 1209 the diocese was an archdiocese . The diocese of Dol was subordinate to the Archdiocese of Tours as a suffragan .
On November 29, 1801 , the Diocese of Dol was dissolved as a result of the Concordat of 1801 by Pope Pius VII with the Papal Bull Qui Christi Domini and the territory was annexed to the dioceses of Rennes and Saint-Brieuc .