In 1941 Lwów (Lviv) passed into German hands. The General Government authorities incorporated the Ossolineum into the structures of the Second Department of the State Library in Lwów (Lviv) (Staatsbibliothek Lemberg). After the German invasion of Lwów (Lviv), Mieczyslaw Gębarowicz, who had previously headed the Art Department of the Lviv Department of the Library of the Academy of Sciences in Kiev (i.e. the de facto department of the Ossolineum, which had been liquidated by the Soviets), became the commissar administrator and later the head of the aforementioned department. The curator of the National Ossolinski Institute at that time was Prince Andrzej Lubomirski. In April 1943 he secretly appointed Mieczyslaw Gębarowicz as the director of the Institute. Gębarowicz thus combined the official position of head of the Second Department of the State Library in Lwów (Lviv) with the secret position of director of the National Ossolinski Institute.
