Roger du Plessis, duke of LIANCOURT (1599-1674), first gentleman of the King's Chamber, friend of Théophile de Viau and Cardinal de Retz, married Jeanne de Schomberg and became, under his wife's influence, a Jansenist; the refusal of a priest of Saint-Sulpice to give him communion provoked a polemic which prompted Pascal to write the Provinciales. L.A.S. "Liancourt", [April 1642, to M. de Chavigny]; 1 page folio. About Cardinal de Richelieu (who will die in December)... "If I had known more about the illness of Monseigneur le Cardinal I would not have been so anxious to write to you, but it has been too secret to leave me the means to testify to you, my father will judge you by the joy that his cure brings me...