Henri François Xavier de Belsunce de Castelmoron (born 1671 at the Château de la Force, in Périgord; died 1755 in Marseilles) was a French Jesuit who became Bishop of Marseille.
His father was Armand de Belsunce, Marquis de Castelmoron, and his mother Anne de Caumont de Lausun. He studied classics in Paris at the College de Clermont or Lycee Louis-le-Grand and then entered the Society of Jesus. In 1699 he left the Society to become Vicar-General of Agen.
The Vie de Suzanne de Foix, a biography of his aunt, was written by him and published while at Agen, 1709. That same year he was made Bishop of Marseilles.
The charity he displayed during the plague of 1720 and 1721 made his name a household word and won for him the title of “Good Bishop”. When the plague broke out a large fleet was taking the Princess of Orléans to Italy where she was to marry the Duke of Modena. The suite of the princess took to flight, and with them all the notables of the city, but Bishop Belsunce remained with a few friends, and together they battled against the plague, till they conquered it. In his address to the Assembly of the Clergy in 1725, Belsunce stated that more than 250 priests and religious perished at that time. But he was the soul of the rescuers and the praises bestowed on him by Alexander Pope and Charles Hubert Millevoye (Essay on Man and Belsunce ou la peste de Marseille) were deserved.
The King of France offered him, by way of recognition, the See of Laon to which was attached the first ecclesiastical peerage of the realm and afterwards the metropolitan See of Bordeaux. Belsunce refused both and contented himself with accepting the pallium sent him by Pope Clement XII.
During his incumbency Belsunce fought against Jansenism. He attended, 1727, the Synod of Embrun where Jean Soanen was condemned. He opposed with all his power Colbert of Pamiers. In spite of the protest of the Parliament of Provence, he instructed his priests to refuse absolution to the appellants against the Bull U***enitus. Nearly all his pastoral instructions are against Jansenism.
Besides the Vie de Suzanne de Foix (Agen, 1709), and his pastoral instructions, we have from his pen Le combat chrétien translated from Augustine of Hippo’s De Agone Christiano and L’art de bien mourir translated from Bellarmine’s De Arte Bene Moriendi, also Antiquités de l’Eglise de Marseille (Marseilles, 1747-51). All these writings were published by Jauffret under the title of Oeuvres de Belsunce (Metz, 1822).