His father was Charles de La Fontaine, maître des eaux et forêts – a kind of deputy-ranger – of the Duchy of Château-Thierry; his mother was Françoise Pidoux.
Hans far var Charles de La Fontaine, maître des eaux et forêts, en form for offentlig skytte, for hertugdømmet Château-Thierry; hans mor var Françoise Pidoux.