El caballero andante

This was the one time John Everett Millais painted a female nude, and it went badly enough that he never tried again. He showed it in 1870: a woman stripped and bound to a tree, a knight in armour cutting her free. Victorian reviewers were unsettled, partly because she first looked straight out at the viewer, which read as far too bold. The painting did not sell. So Millais took a knife to his own canvas, cut out the head and shoulders, and repainted her turning modestly away. The original face did not go to waste. He stitched it into another canvas and exhibited it two years later as the head of a drowned martyr. Henry Tate bought the altered picture and gave it to the nation in 1894.