Life in the French Country House also by Mark Girouard
Both books start out with the medieval houses and households of lords and kings and lesser gentlemen and trace the history up to modern times. Which means, naturally, that they also trace the fortunes and practices of the nobility who lived in them. Not the same information for both. For instance, he talks about how one was supposed to become a marquis or duke, or baron, or count: You had your land declared a marquisate, a dukedom, a barony, a county. In theory, you sold the land, you lost the title. In practice, you could give yourself the title and no one cared because it had no legal significance. He doesn't talk about how English nobles got their titles.
Better to read English Country House first. The other contrasts French practice with English more often so it helps to know the English first.
The households of the medieval English were enormous -- and virtually all male. A warband having undergone some modifications. And many members of it were high ranking; a servant could have three servants of his own. And the whole intricate framework of ceremony worked about it. These declined out of medieval times for all sorts of reasons: decline in violence, high-ranking men went into other fields which opened up, and royal disapproval of large groups. Also, the expense.
The grand medieval hall where everyone ate retreated into all kinds of rooms for private eating. Again and again. Because as soon as, say, the lord ate in the great chamber instead of the hall, he would start eating in the privy chamber when he wanted some privacy.
And the introduction of female servants, and the addition of libraries, and how the rise of the merchant class changed their ethos -- it was a major factor in their coming to regard some things as proper for the country and some for the city, because they represented the country and the agriculture while the merchants represented the city, and they embodied this architecturally.
The slow progress of modern conveniences into the home. Some only because you couldn't get servants to put up with doing without them.
Now, in a French house, there was a lot less ceremony. Partly because in France, you did not work from the immensely graduated degrees of status. You had nobles -- and everyone of noble descent was noble -- and then the rest of them. They would never eat together, not even with the carefully ranked tables that the English had.
But you had the same sort of retreat into more and more rooms. Not exactly the same -- access was easier in France -- but the rooms did proliferate.
For the French, of course, the houses didn't have the political necessity that the English ones did. You didn't have to persuade your freeholders to vote as you wanted them to. But there was hunting, and then it was also cheaper. It's hard to figure out whether they spent much time in their chateaus because writers in the same era would write "People used to go to their chateaus a lot when I was a child but not any more" and "People go to their chateaus a lot more than they used to when I was a child." Courtiers dancing attendance on the king didn't have much chance, but other apparently did.
After the revolution, of course, you got a lot more. The English nobles lived in their country houses; the English didn't have a revolution, therefore the French nobles should have, and should now, live in their country houses. QED
And a large number still have their chateaus, although it can still be interesting keeping them going.
Useful books for writers. Especially since they offer different possibilities.