After the outbreak of the war and the sudden death on 18 September 1939 of Ludwik Bernacki, the director of the Ossolineum, Gębarowicz found himself alongside Kazimierz Tyszkowski and Władysław Wisłocki, one of three directors of the Institute. In December 1939 the Soviet authorities had inserted as director, their Polish Communist place-man, Jerzy Borejsza.