Saint-Brieuc Cathedral was the seat of the Bishopric of Saint-Brieuc, one of the nine ancient dioceses of Brittany, and continues to be the seat of the enlarged Bishopric of Saint-Brieuc-Tréguier, as it has been known since 1852. Some of the relics of Saint Brieuc himself, the 6th-century founder, are still kept in the cathedral. The present building however was built in the 14th and 15th centuries.
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