Several well-known collectors have owned the portrait, including Joan Whitney Payson, the philanthropist and former owner of the New York Mets, and the financier Henry Kravis and his wife, Marie-Josée Marie-Josée Kravissident of the Museum of Modern Art.
The portraits, including the paintings that constitute the frames, cost twenty-five thousandollarsrs.
The portraits include protesters, one of whom is naked from the waist up with a shaved head, arms raised.
The portraits include biblical prophets and early Shaker leaders, with Ann Lee in the place of honor at the upper left and -- the only secular figure -- Christopher Columbus in the same row.
The portraits include Tchaikovsky, Gogol and Sergei Eisenstein, Anton Krasovsky, the political journalist and gay rights advocate, and Dmitry Chizevsky, whose left eye was destroyed, says Dumas's note, in a homophobic attack.
The subjects of the portraits include family and friends, but Brown has also persuaded a number of well-known sufferers of depression to pose for him, including Tony Blair's former director of communications, Alastair Campbell, and an array of names from stage and screen.
The portraits include Roots Manuva, whose first album was recorded in a community studio on the Angell Town estate, fashion designer Dame Vivienne Westwood, former soldier Johnson Beharry, who was awarded the Victoria Cross for bravery in Iraq, and the gay rights campaigner Peter Tatchell.
He spoke to the BBC about the process behind some of the portraits, including the final photograph ever taken of Tony Curtis.
His 1947 image "Twelve of the Most Photographed Models of the Period," a group portrait, includes, at its center, Lisa Fonssagrives.
Following the discovery, new theories have now been applied to the well-known portrait, including a suggestion the artist may have introduced the ermine into the painting to symbolise Gallerani's lover, later enhancing the animal to flatter his patron.
