wealthy aristocrats (and/or nobles and/or merchants) living on manorial estates in the countryside and owning slaves or serfs.
Landed gentry, exempt from mandatory military under Catherine The Great of Russia, retired to their estates to live like hedonists; this is part of the reason why Russiansociety actually degenerated to the point of revolution by 1917.
In Britain, 'gentry' is the term applied for those people who belong to the upper class with country estates often (but non always!) farmed on their behalf by others, and who may be without a peerage or other hereditay title.
"Ok, Tommy darling, now that you're in London, there's a thing you must know. This isn't America...So, before we go out visiting my cockney friends, dress well, drive on the LEFT side, mix with the local gentry, and don't crash Tarquin's Bentley..."
"Ugh, ok, honey. I promise. Who's this Tarquin anyway? "
Also known as Princess Meredith NeEssus from the Laurell K. Hamilton 3-novel series about fae. Merry Gentry is a detective in Los Angeles that is also co-heir with her cousin to the UnSeelie throan. She has to be with child in three years in order to obtain it. She sleeps with many of the royal guard. Books highly erotic.