In the summer of 1911, David Lloyd George, then Chancellor of the Exchequer, hired a young school teacher called Frances Stevenson to tutor his daughter in the summer holidays. He was forty-eight, and married with four children. She was twenty-two and had recently graduated with a degree in classics. She was highly intelligent as well as very attractive, and Lloyd George soon began to employ her as his secretary.

At the beginning of 1913 they became lovers, on terms spelt out by Lloyd George with ruthless clarity: he would not leave his wife for her, nor would he risk his career. She was to become his private secretary, run his office and share his life as fully as his family and the need to avoid a scandal would allow.

Their secret relationship was to last for thirty years until his wife’s death finally allowed Lloyd George to marry her in 1943, less than two years before his own death.

John Campbell’s compelling new book is the first detailed study of this extraordinary relationship – one that was known about by everyone in politics but never revealed in the press – and of the strains that it placed on both parties. Frances longed to come out of the shadows and, even more, to have a child. In 1929 she finally gave birth to a daughter. But who was the father? Combining sex, romance, family feuds and high politics, this book tells a remarkable tale.

John Campbell has based his account on letters, diaries and a vast range of material, published and unpublished. The book shows once again his particular ability to synthesize a wide variety of sources into a story that is at once riveting and wholly convincing.