Georgette Heyer wrote The Corinthian a few months after the tragic death of her brother-in-law, a close friend, in one of the early battles of World War II, and under the terrible fear that her husband would soon be following his brother into battle, and that her own brothers would not survive the war. She worried, too, about other family friends, and feared that the war (with its paper rationing, which limited book sales) would make her finances, always straitened, worse than ever. She could not focus, she told her agent, on the book she was supposed to finish (a detective story that would eventually turn into Envious Casca) and for once, she avoided a professional commitment that would earn her money, for a book she could turn to for pure escape. Partly to avoid the need of doing extensive research, and partly to use a historical period that also faced the prospect of war on the European continent, she turned to a period she had already researched in depth for three previous novels: The Regency.
In the process, she accidentally created a genre: The Corinthian, a piece of improbable froth, is the first of her classic Regency romances, the one that would set the tone for her later works, which in turn would spark multiple other works from authors eager to work in the world she created.
[Misunderstandings, silly lovers, cross-dressing and a murder; spoilers.]