The prime instigator for the creation of the Polish Library in Paris was Karol Sienkiewicz, who had managed to assemble the already existing book collections in the history and statistical departments of the Towarzystwo Literackie w Paryżu, and the Towarzystwo Pomocy Naukowej, the Polish Literary and Scientific Aid societies.
To satisfy French legal requirements, Czartoryski took on formal ownership of the institution, thus securing its material survival.