In 1937, after Prince Adam Ludwik's death, his son Prince Augustyn, took over as head of the family. He married Princess Dolores Victoria Maria de las Mercedes de Borbon y Orleans and spent most of his time in Poland. Then, in August 1939, Europe was thrown into turmoil with the events of World War II, and the museum was forced to prepare for war. Sixteen cases packed with the most precious objects were transported and stored in Sieniawa, while the rest of the collection was carried down to the cellars of the museum, where unfortunately the Germans found the cases and looted the tradable objects. Luckily, although the Leonardo and other pictures were roughly handled, they were not damaged.