HI, 'Sieur ' is effectively the owner of an estate called........ The estate is not NOBLE, and therefore the owner does not have feudal rights over it, like the wonderful' Droit de Seigneur'(!!!), So the bearer of this title is purely the owner of a particular piece of land designated as .......... More often than not, the owner was quite rich and on the way up! His next xtep would be to purchase a 'Noble' fief, (i.e. a Manor with feudal rights) which would get him further up the social ladder, or, in the event that he could bargain with the Royal demesne, he could have the estate turned into a 'noble' one and thus acquire 'nobility' through the ownership of a 'noble' estate rather than having it conferred upon him. In short, your ancestor was of a family some local standing, who probably obtained his wealth from a notarial or legal activity. hope this answers your question. There is another angle to this, however. It could be that the owner was a Noble but his father did not have enough 'noble' estates to pass around, so he gave him one that was not! Pierre