He was the son of a silk manufacturer at Lyon , where he was born , originally intended to follow his father 's business ; but as a volunteer in the cavalry of the national guard at Lyons in 1792 his military ability got him rapid promotion . He was the son of a silk manufacturer at Lyon , where he was born , originally intended to follow his father 's business ; but having in 1792 served as volunteer in the cavalry of the national guard at Lyons , he manifested military abilities which secured his rapid promotion .