In 1682, a young woman in the throes of a passionate affair flees her parents’ home in Surrey to seek a new life in London. A scandal in its own right, but this is no ordinary young woman: Lady Henrietta Berkeley is the daughter of one of England’s most powerful men, and her lover is her own sister’s husband. As news of this notorious adulteress spreads, her flight, capture and the lawsuit that follow tear through society as the scandal of the century. To Aphra Behn, England's first professional female writer – herself condemned as a scarlet woman of loose morals – Henrietta’s trial would be more than a source of shock and intrigue: it would inspire her to write Love Letters Between a Nobleman and His Sister, an outrageous and bestselling political fiction and arguably the first novel in English literature. Lisa Hilton's new history offers a surprisingly original theory on the origins of one of England's most celebrated playwrights.