The Criminal Conversation of Mrs Norton, By Diane Atkinson

A mother, a wife, a lover – and a fighter

By 1836, gossip about the relationship between the Whig prime minister Lord Melbourne and the clever, vivacious and head-turningly gorgeous Mrs Caroline Norton had been circulating for several years. Then, Caroline's husband George – a dull, violent, lazy man who'd encouraged and used his wife's friendship with Melbourne for his own advancement – sued the prime minister for criminal conversation: adultery, in other words. A lively account of the resulting cause célèbre opens Diane Atkinson's captivating fifth book.

Although Melbourne and Caroline probably were lovers, the jury found in Melbourne's favour. This outcome marked resolution for Melbourne, but not for Caroline. As was his legal right, a bitter Norton denied his estranged wife access to their three children and, having snaffled her income (she was a successful author) along with her meagre inheritance, left her financially dependent on relatives and friends. Everything Caroline earned, owned or had been bequeathed was, in law, her husband's property.

What makes her story significant as well as fascinating is that she didn't just try to negotiate the best outcome for herself and her children within the contemporary legal framework. She fought to change the law. She lobbied friends and acquaintances in Parliament to introduce and support the Infant Custody Bill, and wrote two pamphlets about it. "It is a strange and crying shame," she wrote, "that the only despotic right an Englishman possesses is to wrong the mother of his children."

After a frequently interrupted journey through both houses of Parliament, the Infant Custody Act was finally passed in August 1839, making Caroline – who always denied being a feminist – responsible for what Atkinson calls "the first piece of feminist legislation in Britain".

Atkinson leavens the gripping, heart-rending story of Caroline's struggle for justice with a slew of deliciously eyebrow-raising anecdotes. Once or twice, these froth over the main narrative, but that's a minor complaint about a pacy book that's as bright and fascinating as its heroine.

To sponsor or read an extract from Lisa Gee's biography of William Hayley (1745 - 1820), go to unbound.co.uk/books/hayleyworld