Portrait of Madame X

by John Singer Sargent This painting shocked 19th century Paris society for a number of reasons. For one thing, the subject, Madame X, was rumored to be known for her numerous extramarital affairs. For another, the plunging neckline of what might be the first LBD.

Originally, one of the straps was painted as slipping off the shoulder, but Sargent relented and painted it in place.