In fact Dupin was both her married and maiden name. Charles' father was a lawyer and Charles himself was brought up in Nivernais, the region of his birth. Nivernais was not part of the French crown when he was born there, being owned from 1659 by Cardinal Mazarin and his descendants until 1790 when it became the département of Nièvre. Charles was the middle of the three sons of his parents; his older brother André also achieved fame in his profession as a lawyer.
Charles' ama ay isang abogado at Charles siya mismo ay nagdala sa Nivernais, ang mga rehiyon ng kanyang kapanganakan. Nivernais ay hindi bahagi ng French korona kapag siya ay ipinanganak doon, na pag-aari mula sa 1,659 sa pamamagitan ng Cardinal Mazarin at ang kanyang mga supling hanggang 1790 kapag ito ay naging ang Departement ng Nièvre. Charles ay ang kalagitnaan ng ang tatlong anak ng kanyang mga magulang; kanyang mas lumang mga kapatid na lalaki Andre din makakamtan katanyagan sa kanyang propesyon bilang isang abogado.