 Lefaucheux was the subject of the 2009 biography, "Patron de Renault, Pierre Lefaucheux (1944-1955)" by Cyrille Sardais.Born at Triel-sur-Seine, and descended from the French inventor Casimir Lefaucheux, Lefaucheux was second of the four children of Pierre André Lefaucheux and Madeleine Dulac.He volunteered for military service in September 1917, his record of military achievement in the First World War being crowned with his receipt of the Croix de Guerre.