Love & Folly - The Conway Trilogy, #3

Lady Jean Conway is wildly in love with Owen Davies, a Shellesque poet who is cataloguing the Brecon library, whereas her twin, Lady Margaret, has a tendre for Lord Clanross's private secretary, who is in love with Jean. Both Johnny Dyott, the secretary, and Owen are involved in Radical politics. So is the Earl of Clanross, who wants an immediate reform of Parliament, to the horror of Lady Anne, his political sister-in-law.
His wife, Lady Elizabeth, wants to study comets, and his best friend can't decide whether to give away the fortune he's inherited or buy his wife the country estate she yearns for. These intertwined stories play against a canvas of public events, including the divorce of Queen Caroline, in 1820, the silliest year in English history.