Intelligent, elegant, and socially gifted, the Hon. Lady Emily Lamb was born into privilege—her godmother was the infamous Georgiana, Duchess of Devonshire. But Lamb refused to be defined by society's expectations. After an early love marriage to Earl Cowper soured, she took a string of lovers, culminating in taming a rake: the promising, promiscuous Harry, Lord Palmerston.

Placing herself at the centre of glamorous Regency high society with its duels and dissipation, Emily became a leader of fashion, admired by Lord Byron and Thomas Moore. From the balls and sex to the fortunes won and lost, Lamb's life resembled real life Bridgerton—she even inspired the character Cressida Cowper.

But Lamb did much more than host parties. A confidante of Queen Victoria, she used her political genius to engineer her brother, Lord Melbourne, and Harry Palmerston's unexpected leaps into the cabinet, and their eventual premierships. Once they were in Downing Street, she acted as their chief counsels, wrote speeches and memos, conducted press briefings and schemed to defeat her opponents.

Lamb was not only motivated by personal ambition. Fighting against injustice during a period of history when debate raged about democracy, slavery, immigration and divorce, she advocated for progressive causes, including abolition and women's rights. Throughout the dramatic period from Napoleon to the height of Victoria's reign, in which the seeds of modern democracy were sown, social values were transformed, and Britain ruled a quarter of the world, Lamb changed the course of history.