Étienne-Charles was born at the Château de Crux in Nivernais, the last son of Louis Alexandre de Damas, Count of Crux (died in 1763) and of Marie-Louise de Menou (1712-1796), daughter of François-Charles, Marquis of Menou (1671-1731).
He was received from youth into the Order of St. John of Jerusalem but never pronounced his vows as Knight, which later permitted him to marry.

In 1799 he married Anne-Félicité-Simone (Paris, 15 January 1772 - Paris, 25 January 1848), daughter of Armand-Louis de Sérent, Duke of Sérent and Bonne Marie Félicité de Montmorency-Luxembourg, dame d'atour to Princess Élisabeth of France in 1776-92, and dame d'honneur to Marie Thérèse of France in 1799-1823.
Étienne-Charles was born at the Château de Crux in Nivernais, the last son of Louis Alexandre de Damas, Count of Crux (died in 1763) and of Marie-Louise de Menou (1712-1796), daughter of François-Charles, Marquis of Menou (1671-1731). He was received from youth into the Order of St. John of Jerusalem but never pronounced his vows as Knight, which later permitted him to marry.
In 1799 he married Anne-Félicité-Simone (Paris, 15 January 1772 - Paris, 25 January 1848), daughter of Armand-Louis de Sérent, Duke of Sérent and Bonne Marie Félicité de Montmorency-Luxembourg, dame d'atour to Princess Élisabeth of France in 1776-92, and dame d'honneur to Marie Thérèse of France in 1799-1823.
Étienne-Charles de Damas-Crux