Cecilia Gallerani, Leonardo Da Vinci, Oil on Panel, 1483-1485, Czartoryski Museum, Cracow

The Lady with the Ermine (Cecilia Gallerani) Leonardo da Vinci Czartoryski Museum, Cracow, Poland

Andy Warhol - Elephant, 1983 - endangered species series.

"Elephant" -- 1983 -- From the artist's 'Endangered Species' series -- Andy Warhol -- American -- Silk screen print -- Photo courtesy of the Andy Warhol Foundation for the Visual Arts.

Portrait of Mrs Louis Raphael by John Singer Sargent

Cropped portrait of Mrs Louis Raphael by John Singer Sargent

Nonchaloir by John Singer Sargent (detail)

Such a strange pose she strikes for a painting! Nonchaloir by John Singer Sargent (detail)

Marc Chagall - 'Le Cheval Rouge' - (1938-44) Georges Pompidou National Center for Art and Culture, Paris.

¤ Marc Chagall - Le cheval rouge 1938 - 1944 Huile sur toile de lin 114 x 103 cm.

Andy Warhol (1928-1987) Satyric Festival Song, from Martha Graham

Andy Warhol - Martha Graham: Satyric Festival Song, Edition of Signed and numbered on the reverse in pencil by Warhol. Published to commemorate the sixtieth anniversary of the Martha Graham Center of Contemporary Dance.