 Its foreign members and lecturers included Barthold Georg Niebuhr, Johan David Åkerblad, Bertel Thorvaldsen, as well as sovereigns Frederick William IV of Prussia and Charles Albert of Sardinia.Pope Pius VIII gave the Academy the title of "Pontifical Academy".In 1833 an attempt was made to remove the tomb of Raphael, but the Academy protested to Pope Gregory XVI and was successful.