House of Savoy-Carignano - France

France

In anticipation of this inheritance Thomas Francis and Marie did not establish themselves at his brother's ducal capital, Turin, but dwelt in Paris, where Marie enjoyed the exalted rank of a princesse du sang, being a second cousin of King Louis XIII. It was arranged that Thomas Francis, as son of a reigning monarch, would hold the rank of first among the princes étrangers at the French court —- taking precedence even before the formerly all-powerful House of Guise, whose kinship to the sovereign Duke of Lorraine was more remote. He was appointed Grand Maître of the king's household, briefly replacing the traitorous Grand Condé. He engaged the services of the distinguished grammarian and courtier Claude Favre de Vaugelas as tutor for his children.

The prospect of Marie's eventual succession to the Swiss principality of Neuchâtel, near Savoy, was foiled in 1643 by the king's decision to legitimate Louis Henri de Bourbon, chevalier de Soissons (1640–1703), a son of Marie's late brother. This prevented the substitution of Savoyard for French influence in that region, but left Thomas with little more than the empty title of "prince de Carignan". Marie did eventually inherit her brother's main holding in France, the county of Soissons, but this would be established as a secundogeniture for the French branch of the family. After Thomas Francis, the senior branch of his descendants repatriated to Savoy, alternately marrying French, Italian and German princesses.