The Diocese of Beauvais, Noyon, and Senlis (Latin: Dioecesis Bellovacensis, Noviomensis et Silvanectensis; French: Diocèse de Beauvais, Noyon et Senlis) is a Latin Church ecclesiastical territory or diocese of the Catholic Church in France.

Beginning in 1100, a five year long period of ecclesiastical, social and political discord descended upon Beauvais, involving eventually Bishop Ivo of Chartres, Archbishop Manasses of Reims, two papal legates, Joannes of Saint Anastasia and Benedict of Saint Pudenziana, King Philip I of France, and Pope Paschal II.

On the death of Bishop Ansellus of Beauvais in November 1099, it became evident that there were two opposed parties in the business of the election of a successor.

One was the majority of the Chapter and the secular clergy of the diocese, who were accommodated to the social system of society and preferred matters as they were; the other was led by the clergy of Saint-Quentin, who were seeking reform and greater rigor, and who looked to Ivo of Chartres, formerly a priest in Saint-Quentin, for advice and support.

[6] It happened that the ecclesiastical Province of Reims was holding a synod at Soissons, and the leaders of the winning party, the Dean and Archdeacons of Beauvais, went to announce the election and request that letters be sent to the King and the Pope on Etienne's behalf, and they petitioned Lambert of Arras, the Papal Visitor in the province to write to Pope Paschal as well.

[7] The losing party enlisted Ivo of Chartres, who made a detailed investigation into the deeds and character of Étienne Garlande.

In the meantime the Church of Beauvais sank into disorder, with two competing jurisdictions, that of the uncanonical and unconsecrated Étienne, and that of the Vicars appointed by the Chapter in the absence of a consecrated bishop.

[13] On 6 December 1114 a Council was held in Beauvais, presided over by the Papal Legate Cardinal Kuno von Erach (Conon, Kono).

The Emperor Henry V was again anathematized, along with the Bishop of Münster and Count Thomas de Marla, who enjoyed raving the areas of Laon, Reims and Amiens.

The synod accepted his sanctity and authorized the moving of his remains from the convent of Aldenbourg in the diocese of Tournai to the cathedral of Soissons.

The papal Conclave of 1159 had produced a schism between Pope Alexander III and the puppet of the Emperor Frederick Barbarossa, Octavianus de' Monticelli, Cardinal of S. Cecilia, who called himself Victor IV.

The council agreed with the King that Alexander III was the true pope, a judgment that was confirmed in a joint meeting held by Louis VII and Henry II of England at Toulouse in the autumn of 1160.

On 1 June 1427, Bishop Pierre Cauchon, who was a partisan of Philip the Good, Duke of Burgundy, and no supporter of Charles VII, was one of the consecrators of Jacques du Chastellier, the English candidate for the bishopric of Paris.

[18] He fled from Beauvais as Charles' armies appeared in the area, led by Jeanne d'Arc (Joan of Arc).

[19] In 1452 the case was reopened on orders of Pope Nicholas V by Cardinal Guillaume d'Estouteville, cousin of a former bishop of Beauvais, but the proceedings did not lead to a definitive conclusion.

The court issued its judgment on 7 June 1456: "We say, pronounce, decree and declare the said Processes and Sentences full of cozenage, iniquity, inconsequences, and manifest errors, in fact as well as in law.

The Seigneur de Tressures had also ridden out and obtained several thousand troops from various sources, including Robert d'Estouteville, Provost of Paris.

[21] In 875, Bishop Odo, with the consent of King Charles the Bald, as an act of considerable generosity, increased the number of Canons in the Cathedral of Saint-Pierre to fifty.

The new Civil Constitution mandated that bishops be elected by the citizens of each 'département',[32] which immediately raised the most severe issues in Canon Law, since the electors did not need to be Catholics and the approval of the Pope was not only not required, but actually forbidden.

The legitimate bishop of Beauvais, François-Joseph de la Rochefoucauld, declined to take the required oath to the Civil Constitution, and betook himself to Paris, where he was accused and arrested.

[33] In 1791 the electors of 'Oise' assembled and elected as their Constitutional Bishop a priest, Jean-Baptiste Massieu, who had been a teacher, first at Vernon, and then at Nancy.

He was in Paris at the time of his election, serving as an active member of the Ecclesiastical Committee which had drawn up the civil Constitution.