The Duke of Montmorency
Are we linked to the Duke of Montmorency? Francois Henri, the Comte de Bouteville was also Duc de Montmorency & also Duc de Luxembourg. Stemmata Botevilliana implies that there is a link to this family but this requires more research.

The first crusade took place between 1096 and 1100, the conquest of
Jerusalem happening in 1099. From this ancient race of de Bouteville is
descended the present Duc de Montmorency.
This may be seen in the Histoire Geneologique et Chronologique de la Maison Royale de France par le Pere Anselme 1728 folio torn. iv 615, vii 154 & 550, and viii 914. The implication of this is that either Sir Geoffroy de Bouteville or his brother Oliver, alias Olivier, was the ancestor of the Duke of Montmorency too. In the battle of Trente (14th century) there was an Olivier de Bouteville Montville which could possibly be the beginning of the name Montmorency. It is believed that Olivier died at Crecy but this has to be confirmed.