Czartoryski aspired above all to reconstitute—with French, British and Turkish support—a Polish–Lithuanian Commonwealth federated with the Czechs, Slovaks, Hungarians, Romanians and all the South Slavs of the future Yugoslavia. Poland, in his concept, could have mediated the conflicts between Hungary and the Slavs, and between Hungary and Romania. The plan seemed achievable during the period of national revolutions in 1848–49 but foundered on lack of western support, on Hungarian intransigence toward the Czechs, Slovaks and Romanians, and on the rise of German nationalism.