A rare portrait by celebrated painter Francis Bacon sold for £43.4 million ($52.8 million) at Sotheby’s London on Wednesday, the first time the artwork has been auctioned in its almost six-decade history.A rare portrait by celebrated painter Francis Bacon sold for £43.4 million ($52.8 million) at Sotheby’s London on Wednesday, the first time the artwork has been auctioned in its almost six-decade history.