From 1534 La Rochelle and the Province of Aunis were a centre of Calvinism. In 1573 the city successfully resisted the Duke of Anjou, brother of Charles IX of France, and remained the chief fortress of the Huguenots in France. But in 1627 the alliance of La Rochelle with the English proved to Louis XIII and to Richelieu that the political independence of the Protestants would be a menace to France; the famous siege of La Rochelle (5 August 1627 – 28 October 1628), in the course of which the population was reduced from 18,000 inhabitants to 5000, terminated with a capitulation which put an end to the political claims of the Calvinistic minority. The Chapter of the Cathedral of Saint-Louis was composed of eight dignitaries and twenty Canons. The dignitaries were the Dean (elected by the Chapter), the Treasurer, the Almoner, the Grand Archdeacon, the Archdeacon of Fontenay, the Cantor, the Subcantor and the Archdeacon of Bressuire—all appointed by the bishop. A seminary was established by royal order, with an income of 3000 livres, derived from an assessment on all of the benefices in the diocese. The seminary was entrusted to the Jesuits in 1694 by Bishop de la Frezelière, two of whose brothers were Jesuits. During the French Revolution, when the Civil Constitution of the Clergy instituted a national church, and the nation was redivided into dioceses which matched as far as possible the civil departments into which the administration of the state was divided, the diocese of Saintes and the diocese of La Rochelle were combined into the Diocese of Charente-Inferieure. Both Bishop de La Rochefoucauld and Bishop de Coucy refused to take the oath of loyalty to the Civil Constitution, as required by law. They were therefore deposed. The electors of Charente-Infeurieure assembled on 27 February 1791 and elected Fr. Isaac-Étienne Robinet, the curé of Saint-Savinien-du-Port as their Constitutional Bishop. He made his formal entry into Saintes on 31 March, and took formal possession of the cathedral on 10 April. He roused up the anti-clerical feelings of the populace against the non-jurors, but, once roused, they turned against all the clergy, including Robinet.