The Hermitage was opened to the public in 1852. At that time it already included the vast collections of Greek, Roman, Oriental, Middle Ages, West and East europeen and Russian art. In the 19th it purchased paintings of russian masters, but in 1895 they were given to the Russian Museum. The Hermitage funds were enlarged thanks to gifts and purchases of russian collectors.

The imperial Hermitage was proclaimed property of the Soviet state after the Revolution of 1917. The range of its exhibits was further expanded when private art collections from several palaces of the Russian Tsars and numerous private mansions were being nationalized and then redistributed among major Soviet state museums. Hermitage received modern art from private collections of Sergei Shchukin and Ivan Morozov which were nationalized by the Soviet state. New acquisitions included most of Gauguin's later oeuvre, 40 Cubistic works by Picasso, and such icons of modern art as Matisse's La danse and Vincent van Gogh's Night Cafe. In 1931, after a series of negotiations, 22 works of art from the Hermitage were acquired by Andrew W. Mellon, who later donated most of these works to the National Gallery of Art in Washington, D.C, which formed the main part of its collections. Thousands of works were moved from the Hermitage collection to the Pushkin Museum in Moscow and other museums across the USSR. Some pieces of the old collection were also lost to enemy looting and shelling during the Siege of Leningrad in the Second World War. After the second World War the Hermitage received about 40 works by Henri Matisse as a gift from the artist to the museum. Other internationally known artists also gave their works to the Hermitage.