A note in Miscellanies by Thackeray, dated 10 April 1857, describes it as "only the first part" of a longer story which was "interrupted at a sad period of the writer's own life" and never subsequently completed.
This was the period when Thackeray's wife became mentally unstable, throwing his personal life into confusion.When he was preparing to publish the "Miscellanies" 17 years later, he thought for a moment of filling in what was missing, but even then he did not carry out his intention.
His stay there was extended until the summer of the following year, and a series of new publications testified to the determination of the deeply shaken but strong, unbroken spirit to continue the work he had begun.
Though he despises the entire family as ridiculously vulgar, Brandon plans to amuse himself by seducing one or other of the elder girls, who are local belles; but though at first they find him attractive they soon realise he is mocking them and their social milieu.
In fact he is the son of a half-pay colonel who at some cost has put him through Eton and Oxford, with the result that Brandon has come to despise any way of life other than that of an aristocratic playboy.
Unfortunately, he is not wealthy enough to support his tastes and is in Margate because he can hide from his creditors there: "He was free of his money; would spend his last guinea for a sensual gratification; would borrow from his neediest friend; had no kind of conscience or remorse left, but believed himself to be a good-natured, devil-may-care fellow; had a good deal of wit, and indisputably good manners, and pleasing, dashing frankness in conversation with men."
Like Brandon, Fitch is attracted to Caroline and believes himself in love; but in his case rather than seduce the girl he wishes to write her sonnets, worship her from afar, paint her portrait and gradually win her heart.
They are the shabby genteel people of the title, having dubious backgrounds but a small private income (inherited from Juliana's mother, who kept an inn) which allows them to give themselves airs as gentlefolk.
Self-delusion and snobbery are the major themes, along with society's underlying obsession with money: the threat to female innocence posed by unprincipled young men is also present.
Though the planned plot development would have called for greater depth and seriousness, the tone set by the existing first part is exuberantly humorous, with Thackeray employing a mix of sententious satire, acid social commentary and his gift for outright farce.