Sotheby's Contemporary Art Evening Auction will bring together a selection of works by some of the most engaging artists of the 20th and 21st centuries. The sale encompasses three outstanding portraits by Francis Bacon, Albert Oehlen and Jenny Saville, as well as an incredible selection of highlights by Christopher Wool, Louise Bourgeois, Gerhard Richter, Jean-Michel Basquiat and Bridget Riley. Click the image above to view the slideshow.