Hermitage Museum private mansions were nationalized and redistributed among major Soviet state museums. Particularly notable was the influx of old masters from the Catherine Palace, the Alexander Palace, the Stroganov Palace and the Yusupov Palace as well as from other palaces of Saint Petersburg and suburbs. In 1922, an important collection of 19th-century European paintings was transferred to the Hermitage from the Academy of Arts. In turn, in 1927 about 500 important paintings were transferred to the Central Museum of old Western art in Moscow at the insistence of the Soviet authorities. In the early 1930s, 70 more paintings were sent there.
Hermitage Museum insane attacked Rembrandt's painting "Danaë", displayed in the museum. He threw sulfuric acid on the canvas and cut it twice with his knife. The restoration of the painting had been accomplished by Hermitage experts by 1997, and "Danaë" is now on display behind armoured glass. In 1991, it became known that some paintings looted by the Red Army in Germany in 1945 were held in the Hermitage. Only in October 1994 the Hermitage officially announced that it had secretly been holding a major trove of French Impressionist and Post-Impressionist paintings from German private collections. The exhibition "Hidden Treasures Revealed", where