Senlis Cathedral (French: Cathédrale Notre-Dame de Senlis) is a Roman Catholic church and former cathedral in Senlis, Oise, France.It was formerly the seat of the Bishopric of Senlis, abolished under the Concordat of 1801, when its territory was passed to the Diocese of Beauvais.Notre-Dame Cathedral was built, for the most part, during the third quarter of the 12th century, when the royal city of Senlis was experiencing a true "golden age".