Definition of "postillion"

So saying, he ordered the postillion to the horses' heads, there to await his return.

1838, [Letitia Elizabeth] Landon (indicated as editor), chapter XXIII, in Duty and Inclination: […], volume III, London: Henry Colburn, […], page 295

Barouches with gleaming lamps, a couple of gendarmes posted before the doors, a babel of postillions’ cries—nothing...

1842, Nikolai Gogol, translated by D. J. Hogarth, Dead Souls‎