Francisco Goya, 'Saturn Devouring one of his children' (1821-3). Saturn has decided to eat all of his sons. Why? You might ask. Because he was told in a prophecy that one of them would overthrow him. He devours them all, except one - Jupiter, who is exiled to Crete by Saturn’s wife. Jupiter grows up, returns to his birthplace and kills his father in revenge. This is one of the fourteen so-called Black Paintings that Goya painted directly onto the walls of his house. 15 Jun 2012
'Nude Descending a Staircase No.2' by Marcel Duchamp. Now considered a Modernist staple, this work initially caused a stir at the 1913 Armory Show in New York. Prior to that it was submitted to a show in Paris and rejected on the grounds that "a nude never descends the stairs, a nude reclines".