Baptised at the Church of Saint-Sulpice in Paris, in 1687. He was a member of the Montesson family from the region of Brittany in France. In 1709 he married Marguerite Iris de Poix The couple had no children. Eventually at the age of 70 he married Charlotte de La Haye de Riou. His second wife would eventually become the mistress and later still the secret wife of the Duke of Orléans