Catherine collected the way she did everything else - with imperial appetite. After the Gotzkowsky purchase she went after the great European collections one by one. Heinrich von Bruhl's six hundred paintings in 1769. Pierre Crozat's collection in Paris in 1772, acquired with Diderot's help. Robert Walpole's collection from Houghton Hall in 1779, a coup that horrified the English. By the time she died in 1796 she had acquired roughly four thousand paintings, ten thousand drawings, ten thousand engraved gems, sixteen thousand coins, and a library of thirty-eight thousand books that included entire holdings purchased from Voltaire and Diderot - both philosophers had sold their libraries to Catherine in old age, with the agreement that they could keep using them until they died. She built additions to the Winter Palace just to hold what she bought. The Small Hermitage came first, then the Large Hermitage, then the Hermitage Theatre. The collection had outgrown its name long before Catherine ran out of walls.

Catherine did not intend a museum. The Hermitage was her refuge, her cabinet of treasures, opened only to favored guests. The first public museum building - the New Hermitage, designed in heavy Greek Revival style by the German architect Leo von Klenze - opened on 5 February 1852, decades after her death. By then the collection had absorbed Joséphine de Beauharnais's pictures, looted by the French from German collections during the Napoleonic Wars, and a steady stream of acquisitions from across Russia. The October Revolution of 1917 was, paradoxically, the museum's salvation. The Bolsheviks closed the imperial private rooms and declared the entire collection state property. They opened the doors to the public, transferred private aristocratic collections into the museum's care, and turned the Winter Palace itself into part of the Hermitage. What had been Catherine's hermitage from the world became the world's hermitage.

When Germany invaded the Soviet Union in June 1941, the Hermitage staff had a few weeks to act before the siege closed around Leningrad. They packed the most important works into crates and loaded them onto two trains bound for Sverdlovsk in the Urals - a thousand miles east, beyond the reach of the Wehrmacht. About half the collection went. Some went underground in the museum's cellars. The siege lasted nearly nine hundred days. Two bombs and dozens of shells hit the museum buildings. Staff slept in the cellars beside the remaining art and ran guided tours of empty frames for soldiers on leave, describing from memory the paintings that should have hung there. Hundreds of museum employees died of starvation. By November 1945, when the evacuated trains came back, the museum reopened. The frames were filled again. The visitors returned. The Hermitage had survived a war that destroyed much of the city around it.

When Soviet armies took Berlin in 1945, special Red Army units called Trophy Brigades fanned out to seize art from German museums and private collections - much of it itself looted by the Nazis from across Europe. Crates of paintings, sculptures, and antiquities flowed back to Moscow and Leningrad and disappeared into secret storage. For decades the Soviet government denied the works existed. Then in 1994 the Hermitage announced it had been quietly holding seventy-four French Impressionist and Post-Impressionist paintings from German private collections - Degas's Place de la Concorde, Renoir's In the Garden, Van Gogh's White House at Night. The exhibition Hidden Treasures Revealed opened in 1995 and ran for a year. The paintings remain in Saint Petersburg. Some are originally Schliemann's Trojan gold, the so-called Treasure of Priam, which the German archaeologist had smuggled out of Ottoman territory in the 1870s, then donated to Berlin, from where it was taken in 1945. Three governments now have a claim to it. The Hermitage holds it.

The numbers are difficult to absorb. Roughly three million items in the collection - paintings, sculptures, weapons, coins, costumes, furniture, prehistoric artifacts dug from sites across the former Soviet Union. The numismatic collection alone runs to about a million pieces. Only a small fraction is on permanent display. The galleries occupy the Winter Palace, the Small Hermitage, the Old Hermitage, the New Hermitage, the Hermitage Theatre, the General Staff Building across Palace Square, and the Menshikov Palace nearby. To walk through every room would take days even at a brisk pace. Most visitors choose a wing - the Italian Renaissance galleries with the two Leonardos, or the Dutch and Flemish rooms with their walls of Rembrandts, or the General Staff Building's Impressionist collection from Shchukin and Morozov, the great prerevolutionary Moscow collectors whose private holdings were nationalized in 1918. The Russian invasion of Ukraine in 2022 has complicated everything. International loans have largely stopped. The Hermitage Amsterdam severed ties with Saint Petersburg and renamed itself. Catherine's collection, built to bring Russia into Europe, now sits in a country pulling away from Europe again.