1911 Encyclopædia Britannica, Volume 18… (1911)
“ From the barons of Fosseux, a branch of the Montmorency family established in Brabant in the 15th century, sprang the seigneurs de Boutteville, among whom was the duellist François de Montmorency-Boutteville, who was beheaded in 1627. His son, François Henri, marshal of France, became duke of Piney-Luxemburg by his marriage with Madeleine Charlotte Bonne Thérèse de Clermont, daughter of Marguerite Charlotte de Luxemburg, duchesse de Piney. Charles François Frédéric, the son of the marshal, was created duke of Beaufort in 1688 and duke of Montmorency in 1689. ”
