Claudine Guérin de Tencin

Claudine Alexandrine Guérin de Tencin, Baroness of Saint-Martin-de-Ré /ɡəˈræn də ˌtɒnˈsæn/ (27 April 1682[1] – 4 December 1749) was a French salonist and author.

She was the mother of Jean le Rond d'Alembert, who later became a prominent mathematician, philosophe and contributor to the Encyclopédie, though she left him on the steps of the Saint-Jean-le-Rond de Paris [Wikidata] church a few days after his birth in November 1717.

Claudine was brought up at a convent near Grenoble and, at the wish of her parents, took the veil but broke her vows and succeeded, in 1712, in gaining formal permission from Pope Clement XI for her secularisation.

de Tencin spent some time in the Châtelet and then in the Bastille in consequence, but was soon liberated as the result of a declaration of her innocence by the Grand Conseil.

[2] From this time she devoted herself to political intrigue, especially for the preferment of her brother the abbé Tencin, who became archbishop of Lyon and received a cardinal's hat.