The identity of the painting's subject is not known, but it is thought the balding, bearded man in a stiff, starched collar may be Juan Mateos, King Philip IV of Spain's master of the hunt.

CNN: Previously unknown Velazquez portrait discovered

In these heady days of American economic expansion and low inflation, his gloomy pronouncements may sound rather frumpy (Herblock, a cartoonist, always depicted Mr Martin in an old-fashioned stiff collar).

ECONOMIST: William Martin