Dubbed "a mighty poet" by American author Henry James, Titian (1490-1576) remains one of the most celebrated painters in Western art. In the American Gilded Age, Titian paintings became the peerless prizes of leading collectors and quickly rose to the top of art collector Isabella Stewart Gardner's wish list. In 1896, she landed his masterpiece, The Rape of Europa. It became the sole example of his celebrated poesie cycle outside of...