SENLIS. - An ancient diocese and city, seat of a subprefecture in the department of the Oise in France, situated on the right bank of the Nonette river, surrounded by extensive forests. In Roman times it belonged to the second Belgic province; it was then called first Rotomagus, then Augustomagus, and later Silvanectes, from which the present name derives.
The city was part of the Kingdom of Clovis; in 987 Hugh Capet was elected King of France there, and until Henry IV his successors often resided there. In 1417 it was besieged by the Armagnacs, but was liberated by the Burgundians and the English, who remained there until their defeat by Joan of Arc at Montépilley in 1429.
The list of bishops of S. is preserved in a sacramentary (now in the Bibliothèque Ste-Geneviève [BB. 20]) dating from the 9th century, since it was compiled under Bishop Adebert (871-900); but the episcopal list was added in the margin of the Mass canon after the election of Bishop Bernuin in 937; other hands added the following names up to Henry in 1167 or 1168. The first bishop is Regulus, whose feast is celebrated on 24 April; of the next seven, only their names are known; the eighth, Libanius, attended the Council of Orléans in 511, where Gonotiernus went in 549; Malulfus, ca. 584, is mentioned by Gregory of Tours (Historia Francorum, VI, 46); Aigomarus attended the Council of Clichy in 627; Ermenus attended that of Noyon in 814; Godfrey attended those of Paris in 829 and of Thionville in 835; Offredus took part in the Council of Trosly in 909; among more recent prelates, Cardinal F. Rochefoucauld (1615) and the last Monsignor J. A. de la Roquebure are remembered; the latter died as archbishop of Mechelen, where he had been transferred after Pius VII, in the Concordat of 1801, had united the see with that of Beauvais; Pius IX granted the bishop of this diocese the right to add the titles of the suppressed sees of S. and Noyon.
The cathedral, Notre-Dame, is a Gothic construction of the 12th-13th centuries with modifications from the 16th century. It was built on the site of an earlier building and two other small churches dating roughly from the 10th century; begun in 1153, it was dedicated in 1191; but the large transept was completed in the 13th century, when the chapter house and the attached library were erected. The interior measures 72 m in length, and the vaults reach 24 m in height. The choir is provided with an ambulatory, from which five chapels radiate. The aisles and the presbytery have an upper gallery that also runs along the exterior. The façade is flanked to the south by the bell tower, 78 m high with an octagonal upper stage; in the central portal (1185-90) the tympanum is decorated with the coronation of the Blessed Virgin and scenes of her dormition and resurrection; on the sides are statues of prophets and the months of the year; the side portals are in the flamboyant Gothic style. The ancient episcopal palace, with its chapel, dates in part from the 13th century. The church of St Peter,