Paul Aurelian Cathedral (Cathédrale Saint-Paul-Aurélien) is a former Roman Catholic cathedral in Saint-Pol-de-Léon, in France .Saint-Pol-de-Léon (Breton: Kastell-Paol) is a commune in the Finistère department in Brittany in north-western France. It is noted for the 13th-century cathedral which stands on the site of the original church founded by Saint Paul Aurélien in the 6th-century and the Notre-Dame du Kreisker Chapel, with its 80-metre-high spire, the highest in Brittany. It was also the scene of the a battle during the Breton War of Succession, where the Montfortists and their English allies defeated an army led by Charles of Blois.
It was formerly the seat of the Bishop of Saint-Pol-de-Léon, a bishopric established in the 6th-century but abolished under the Concordat of 1801, when its territory was transferred to the Diocese of Quimper.
It is dedicated to its 6th-century founder, the first bishop Saint Paul Aurelian. He was originally from Wales and is considered to have been the first bishop of the Léon area. We know something of Aurélien's life thanks to a manuscript written in 884 by a Landévennec monk. Paul Aurélien was born in Wales in around 490, and educated at the Saint Iltud school. He was ordained as a priest and in 525 left Wales for the continent with a dozen companions. He landed at the Ile d'Ouessant and preached along the north Finistère coast up to the Île de Batz. According to legend, he helped free the Île de Batz from a dragon which was terrorising the local population.