Galatea

Raphael's supreme secular fresco — the sea-nymph in a shell-chariot pulled by dolphins, surrounded by Tritons and Cupids. Raphael wrote that to paint true beauty he needed 'a certain idea' in his mind — the first articulation of the ideal in Western art theory. Michelangelo visited while it was being painted and drew a head in charcoal on the wall — it is still there.