 Berthelot Dartigny was named judge of the Court of Common Pleas for Quebec district in 1791.He ran unsuccessfully for a seat in the Legislative Assembly of Lower Canada for Quebec County in 1792; he was declared elected in 1793 when Ignace-Michel-Louis-Antoine d'Irumberry de Salaberry chose to represent Dorchester in the assembly.He was elected to represent Kent in a 1798 by-election after the death of the previously-elected member, then elected in Quebec County in 1800 and 1804.