Also known as de Marne, born in 1752(?) in Brussels where he was baptised. In 1764 he came to Paris where he studied at the Académie 1769-77 under the history painter Gabriel Briard. He first visited Switzerland and the Dauphiné in 1776 with Nicolas-Antoine Taunay. In 1783 he became a candidate (agréé) at the Academy but never became a full member. He showed regularly at the Salon 1789-1827. He worked for the Sèvres porcelain factory 1809-13 and made a number of landscape and figure etchings. He was made chevalier of the Legion of Honour in 1828 and died at Batignolles, near Paris, on 24 January 1829.
Demarnes work reflects the strong interest in Netherlandish landscapes and genre scenes during his life-time that were extremely popular with contemporary collectors and the taste 'historical' genre scenes in the guise of earlier periods.