Both versions of a Leonardo da Vinci work are to be brought together for the first time in London and Paris, France, following a deal between the Louvre and National Gallery.
The collaboration will see the two variants of Virgin of the Rocks put on display at the National Gallery's Leonardo da Vinci: Painter at the Court of Milan exhibition.
Following the paintings' joint appearance in London between 9 November and 5 February 2012, the works will then move to the Leonardo da Vinci's St Anne exhibition in March.
National Gallery director Dr Nicholas Penny said: "I am quite sure that the experience of seeing these masterpieces juxtaposed will be one that none of us will ever forget or that will ever be repeated."