A postilion or postillion is a person who guides a horse-drawn coach or post chaise while mounted on the horse or one of a pair of horses.[1] By contrast, a coachman controls the horses from the vehicle itself.
Originally the English name for a guide or forerunner for the post (mail) or a messenger, it became transferred to the actual mail carrier or messenger and also to a person who rides a (hired) post horse. The same persons made themselves available as a less expensive alternative to hiring a coachman, particularly for light, fast vehicles.
Postilions draw ceremonial vehicles on occasions of national importance such as state funerals.
On the battlefield or on ceremonial occasions postilions have control that a coachman cannot exert.