The story of Leda and the Swan is a Greek myth which is told in various versions. Leda, the wife of the king of Sparta, was loved by the god Jupiter. He transformed himself into a swan and came to lie with her. As a consequence of their union she bore the twins Castor and Pollux, who were hatched from eggs. The subject was popular during the Renaissance.
The design appears to derive from a classical motif known from copies after sarcophagus reliefs and gems. The pose is similar to that of Michelangelo's 'Night' (Medici Chapel, Florence).
The work is probably an old copy after a painting of this subject by Michelangelo which he made in 1530, in tempera, for the Duke of Ferrara, but which was sent instead to the King of France.