On 1 July 1697 Pope Innocent XII, at the request of King Louis XIV of France, canonically erected the Bishopric of Blois from territory of the Diocese of Chartres. The Archdeacon of Blois had up to that time been a dignity in the Church of Chartres. The diocese was created in order to combat the considerable Huguenot influence in the southern part of the Diocese of Chartres. Since the new diocese had need of a cathedral, the parish Church of Saint Solenne was chosen; the church had been severely damaged in a fire in 1678, and it was in the last stages of reconstruction in 1697. It was renamed the Cathedral of Saint Louis. With a new cathedral, a new Cathedral Chapter was required. The canons of the Collegiate Church of Saint Salvator, whose church had been sacked and destroyed by the Huguenots in the previous century and only gradually rebuilt, were transferred to the new Cathedral of Saint Louis. The dignities were the Dean, the Precentor, the Subdean, the Provost, the Treasurer and the Prior of S. Solenne. Twelve additional Canons were instituted, to be named alternately by the King and the Bishop. In addition thirty-two chaplains were created, one of whom would administer the Church of Saint Salvator. The benefices which had been in the gift of the Collegiate Chapter of S. Salvator continued to be under the control of the Canons, who also named the Canons who were to preside at S. Salvator on certain days. To support the Canons of the Cathedral of Saint Louis, the income of two monasteries and five priories was redirected by papal bull. Even so, since the number of twelve Canons was thought to be too small for a cathedral, the Chapter of the Hospital of S. James was also transferred to the Chapter of Saint Louis by the first bishop, David-Nicolas de Berthier, with the consent of all parties. In 1753 there were eighteen Canons. All cathedral chapters were dissolved by order of the Constituent Assembly and the Legislative Assembly by virtue of the Civil Constitution of the Clergy in 1791. On 2 July 1699 Bishop de Berthier created two Archdeacons, who were added to the dignities of the Cathedral Chapter. At the beginning of the Revolution, the Constituent Assembly decided that the number of dioceses in France was excessive, and that approximately fifty of them could be eliminated. Those which survived would have their boundaries changed to coincide with new political subdivisions of France, called 'départements'. This was contrary to Canon Law. Blois belonged to the Department of Loire-et-Cher in the Constitutional Church erected by the National Constituent Assembly and its successor the Legislative Assembly. On 18 February the electors of the department elected Henri Gregoire as Bishop of Loire-et-Cher, who liked to call himself Bishop of Blois, even though the legitimate Bishop of Blois, Alexandre-François de Mazières de Thémines was alive and in exile. Religion was abolished during the Reign of Terror, and the Constitutional Church along with it. When religion was restored in 1795, Gregoire made considerable efforts to revive what was left of the Constitutional Church; he held a diocesan synod in September 1800. The Concordat of 1801 gave Loir-et-Cher to the Diocese of Orléans, and the Diocese of Blois was canonically suppressed by Pope Pius VII. When Pius called for the resignations of all the bishops of France, Constitutional and non-juring both, Bishop de Thémines refused, and entered into schism himself. On 27 July 1817 the Diocese of Blois was canonically re-established by Pius VII, though difficulties between the Vatican and French National Assembly retarded the full implementation of the new Concordat. Before the French Revolution, the Diocese of Blois was less extensive than at present, almost the entire arrondissement of Romorantin having been subject to the Bishopric of Orléans, and the Bas-Vendômois to the Bishop of Le Mans previous to 1817. Bishop Alexandre-François de Thémines, who was Bishop of Blois in 1776 and died in exile in Bruxelles in 1829, was one of the most obstinate enemies of the Concordat. It was not until 1823 that Pius VII appointed a new Bishop of Blois.
