This book is an easy read and focuses on the women in the life of David Lloyd George (mainly his wife, mistress and one of his daughters). The author draws on what seems to be a vast amount of historical record (letters and diaries mainly) but she states that his mistress's diaries were written with the intention of being published and Lloyd George at times told her what to write. Despite this, the author treats them as being a frank record of events whereas anything written for publication can't be.
Also, in the 21st century I'm surprised the author doesn't take issue with the fact (as she says in the book) that Lloyd George would have sex with women who were in effect unable to say no (as they were in awe of his fame or were employed by him). That abuse of his power especially in a time when there was great poverty and women had few choices is deeply unpleasant and is skated over by the author who is keen to see him as a 'great man'.