As someone who enjoys detective novels, I was naturally drawn to this non-fiction book about a real life private detective who achieved fame and success in the late Victorian era. His name (at least the one by which he was best known) was Henry Slater and he was the owner of Britain’s leading detective agency. This new book by Nell Darby explores Henry Slater’s life and career and looks at the world of the early private detective in general – the backgrounds they came from, the type of cases they dealt with, the methods they used and the problems that could arise from those methods.

The Matrimonial Causes Act 1857 is one of the key factors that gave rise to the private detective in the second half of the 19th century. This made it possible for people to request a divorce through the law courts (rather than through a private Act of Parliament as previously) as long as they could prove their spouse had committed adultery. Women would also need to prove one other offence, such as desertion or cruelty. But how could people obtain evidence to show that their partner had been unfaithful? By employing a private detective, of course, and asking them to shadow their husband or wife and look for proof of infidelities. And what do you think happened if the detective couldn’t find any proof – and their client was paying them to deliver results?

Slater’s Detective Agency, who operated from offices in London’s Basinghall Street, advertised all sorts of detective work, but most of their business relied on divorce cases. It was one case in particular that brought about their downfall. Having been hired on behalf of a Mrs Kate Pollard to help her divorce her husband, the agency resorted to underhand methods to get the evidence they needed and were betrayed by a former employee with a personal grudge against Henry Slater. This led to a trial which damaged Slater’s business and exposed his true identity. The Pollard case and the trial which followed form a large part of the book, although Darby moves back and forth between that story, a personal biography of Henry Slater himself and a general history of private detective agencies.

This is a fascinating book and has clearly been very well researched (there’s a long bibliography and an extensive section of notes), but it wasn’t quite what I expected. I thought there would be details of more of Slater’s cases than just the Pollard one and more discussion of the other types of work the agency carried out as well as divorces, but maybe there just wasn’t enough information available to do that. I can’t agree with other reviews saying the book reads like a detective novel as there’s very little actual ‘detecting’ being done and certainly not much similarity between Henry Slater and Sherlock Holmes, whose adventures were appearing in print during the same period that Slater was operating. The jumping around from one topic to another also disrupts the flow of the book and meant I couldn’t become as immersed in it as I would have liked.

Still, I enjoyed learning about Henry Slater and how he established his agency, how he found work first through advertising and then through the strength of his fame and reputation, and how he faced challenges from rival companies. It seems that although Slater can be admired for what he achieved in building his business up from nothing and reaching the very top in his chosen profession, he was less skilled in handling his personal relationships with friends and employees – and this, together with his determination to keep his perfect record in winning divorce cases, is what led to his demise.

I was intrigued by the occasional mentions of the women detectives Slater employed, particularly the ones described as ‘cyclist detectives’ who followed their suspects by bicycle. I’ve discovered that Nell Darby has written another book, Sister Sleuths: Female Detectives in Britain, which sounds like a good companion to this one and I’m sure it would be an interesting read as well.

A prominent Victorian-era private detective, Henry Slater built a successful agency through innovative methods. However, corruption within the agency led to a scandalous trial that ruined his career. This book tells the story of Slater’s rise and fall, while also exploring the Golden Age of private detection. It examines the detectives, their clients, and the crimes they investigated.

This is a fascinating story. Despite its successes, Slater’s agency in many ways was a house of cards, and one scandal was sufficient to bring it all down. This book made it clear that private detection was a seedy business in this era, yet was forced to maintain a sheen of respectability in order to gain the trust of clients. The book is written in a storytelling style that makes it entertaining and easy to read.

Thanks, NetGalley, for the ARC I received. This is my honest and voluntary review.

Fact or fiction- truth or hyperbole or worse. Harry Slater advertised himself as Britain’s Greatest Detective and were it not for his hubris, he might have continued the myth. But like so many others, he believed his own, trumped up, press clippings and thought he was untouchable. From treating the people upon whom he most depended in a shabby way or being less than moral and legal in his dealings, he would tumble and tumble hard.

It all revolved around a divorce case where the drunken layabout husband could not be depended upon to commit adultery so his wife would be granted her divorce. His men tried everything but came up short. Finally, out of desperation they contrived the situation and bribed witnesses to confirm the husband’s misdeeds. But Harry had not kept his friends close and his enemies closer and when one former friend decided it was time for his comeuppance, Harry’s misdeeds were laid bare for the world to see.

It is a fascinating story and a cautionary tale. Just because a claim is made, it does not mean it is true. Four purrs and two paws up.

I enjoyed this book. I have been reading a few books recently about detectives and the development of the police force in Victorian England, so this book was a great resource to add to my knowledge. Henry Slater's story is a fascinating one and I really appreciated the level of research put into the book by the author. I'd love to know how the author turns such in-depth historical research into such an engrossing read! This is the perfect book for those interested in crime history and the world of detectives.

You are in for an unexpected treat. I grew up loving Sherlock Holmes, Poirot and any detective story I could get my hands on. I was so excited to discover this book and its look at a real life detective & his detective agency.This book was so well written it is obvious the amount of research and hard work the author put into it . In this book we look at private detective Henry Slater we see how his team and their bad choices soon brought down his business & reputation. It shows the skills Slater had at blending in with people and situations and his skill at finding answers. Written for knowledge however I found myself feeling like I was reading a novel, like a Holmes novel itself. Perfect for anyone who is interested in true crime, and historical crime. You can't even imagine the detail and time that went into creating this book. I couldn't put it down. It was absolutely fascinating.
Thanks to the publishers & NetGalley for allowing me to enjoy this book. I highly recommend this book. I hope that this author creates more for us to enjoy.

A very interesting book on a man I knew absolutely nothing about. His rise and fall as the top Victorian private detective of his time. A true story not just about an individual but social history in general.
M thanks to NetGalley and Pen and Sword for this arc in exchange for an unbiased and honest review.

A deeply informative book. The author has clearly put a lot of research into this, and as a historian I appreciate the time and effort it must have taken to write. A must read for anyone interested in Victorian detectives and social history.

I received a free copy of, Britain's Greatest Private Detective, by Dr Nell Darby, from the publisher and Netgalley in exchange for an honest review. Henry Slater was the best private detective of his time. Henry was not as clean cut as he portrayed himself to be. This was a really good read.

I felt this book was well-written and gave a lot of insight into Henry Slater and his life as a private detective. Definitely for fans of Sherlock Holmes and other British detectives.

I appreciated the amount of research that went into the book and recognize that Dr Nell Darby put in a lot of time to create this work.

My opinion of the book is that I wish it was more novel based and less explicitly factual based. I liked learning about the different parts of history, but wasn't as engrossed as I might have been with more of a novel type book.

After the Matrionial Causes Act of 1857 made divorces easier in England, private detective agencies took off. Although they advertised that they took on cases of fraud, missing persons, etc. watching spouses in order to help get a divorce was the focus of most agencies. It certainly was the case for Henry Slater's detective agency- and it ended up leading to the agency's downfall.

This book has clearly been well researched and gives the reader good insight into the often Wild West approach to detective agencies popping up across Great Britain in the late Victorian and early Edwardian era. The focus, Henry Slater and his agency, is a prime example of what worked using the latest marketing methods- but not necesarily the facts. Just like today's advertising, Slater could massage words to say one thing, even if they weren't entirely accurate.

The book goes back and forth between the main story- that of the agency trying to prove a man named Tom Pollard was unfaithful to his wife so she could divorce him- and meandering biographies of the people in the story, the history of the agency, and private detectives in general. This bouncing back and forth wasn't ideal for keeping the story's flow going or keeping me engaged. Serious repetition issues also annoyed me and had me skimming large sections. The end of the book, actually covering the trial, was a little better written, and engaged in examining attempts at class distinctions and judgements by the lawyers and newspapers involved in biasing (or trying to bias) the public in the case against the agency. This was the more interestesting part to me and I wish more of the book had examined evidence and facts like this part did.

Overall, not a bad introduction for someone who wants to begin exploring the emergence of rivate detctives in Britain. Definitely look at the bibliography for potential resources.

I received a DRC of this book from NetGalley in exchange for an honest review

Dr. Nell Darby’s Britain’s Greatest Private Detective is an absorbing and meticulously researched exploration of the rise and fall of Henry Slater, a man whose name was once synonymous with private detection during its Golden Age. Combining historical analysis with a compelling narrative, this book not only sheds light on Slater’s life and career but also provides a fascinating glimpse into the evolution of private detective work in Victorian and Edwardian Britain.

At the heart of the book is the enigmatic Henry Slater, a pioneering private detective who built a thriving agency in London’s Basinghall Street. Dr. Darby masterfully captures Slater’s rise to prominence, portraying him as a shrewd, modern operator who leveraged technology, media, and innovative publicity campaigns to dominate his field. The vivid details of Slater’s methods—blending charm, infiltration, and intelligence—bring to life a profession that straddled the line between glamour and grittiness.

However, the story of Slater is not merely one of success. Dr. Darby delves into his catastrophic downfall, precipitated by a fateful betrayal and a public trial so scandalous that it drew the attention of Winston Churchill himself. The courtroom drama, intertwined with the revelation of Slater’s true identity, reads like a real-life detective novel, and Dr. Darby handles it with both scholarly precision and narrative flair.

What sets this book apart is its broader examination of private detective work during this period. Dr. Darby contextualizes Slater’s career within the burgeoning demand for private investigation services and explores the diverse backgrounds of those who became private detectives. She also investigates the motivations of clients—what drove them to seek the services of these detectives—and the moral and legal complexities of the profession.

Dr. Darby’s writing is both scholarly and accessible, making this book equally appealing to academics and casual readers interested in crime history. Her attention to detail is evident in the rich descriptions of London’s social fabric, the interplay between class and profession, and the innovations in private detection that paved the way for modern investigative work.

This is more than a biography of Henry Slater; it’s a deep dive into an era when the private detective was both celebrated and scrutinized. By contrasting Slater’s real-life exploits with the fictional fame of Sherlock Holmes, Dr. Darby creates a fascinating juxtaposition between reality and literary legend.

Britain’s Greatest Private Detective is an engrossing read for history enthusiasts, true crime fans, and anyone curious about the origins of private detection. Dr. Darby’s work breathes new life into an overlooked profession and the man who once reigned supreme within it, offering a nuanced look at a time when secrets were currency, and betrayal could be ruinous.

When I began this book, I couldn't imagine how one single divorce case could bring about Slater's complete downfall. There really are so many possibilities, if you think about it. Maybe the whole thing could have been avoided if he hired better people. Although, he probably taught them exactly those tactics, so the whole 'I was sick, don't blame me' doesn't hold up. He probably taught them exactly what to do.

I enjoyed this book so much. I definitely would recommend this book to any non-fiction reader. Even those readers who love historical fiction might enjoy this!

Thanks to NetGalley for the free Kindle book. My review is voluntarily given, and my opinions are my own.

This was a really well done book about Henry Slater, I really didn't know anything about it and thought this had fantastic information going through this. Dr Nell Darby wrote this in a way that worked with the reader and brought Henry Slater to life.

A fascinating non-fiction book that reads like a novel.
Things are always changing and evolving in response to market forces, in the modern day it is AI that is influencing the job market. In the 19th century, a change to the laws governing divorce created a new need…for private detectives. The new laws meant warring partners could legally separate… so long as they had evidence of infidelity. Cue the rise of the private detective.
One man who spotted a niche in the market and jumped at the opportunity was Henry Slater (…if indeed that was his name, but you need to read the book to find out.) Slater established a private detective agency with a 100% success rate at achieving divorce settlements. He had an eye for marketing and (as his tale unravels) a man who was a stranger to truth.
This book is fascinating on so many levels, indeed, I read it with the panache usually lavished on a page-turning novel, such were the strands of intrigue. This is a story of greed, invention, human frailty, and a court case attended by a young Winston Churchill (because it caught his interest, not because he was involved.) It is a cautionary tale of arrogance, where a belief in ‘fixing things’ comes unstuck and the self-named “Greatest detective in Britian” is the author of his own downfall.

Well written and well researched book about the rise of private detectives in Victorian Britain - in particular, that of Henry Slater, the owner of the most well-known agency. His empire came tumbling down over a divorce case, where some of his team behaved appallingly and faked evidence. But nothing was quite as it seemed, including Henry Slater himself: a man who changed his identity several times on his quest to climb the social ranks, and it was very hard for the courts to pin down exactly who he was and where he'd come from. Henry was very good at covering his tracks, and the author had trouble finding out what really happened to him afterwards.

The book is a fascinating glimpse into the class system and how people could manipulate it. You can see why the nation was gripped by the court case: the salacious details, the way everyone tried to hoodwink everyone else, and who was actually guilty of what.

Fans of true crime will enjoy this one.

As a child, I devoured Sherlock Holmes stories. I loved the idea of a private detective and Britain’s Greatest Private Detective adds real substance to that unknown and lost world. It’s an incredible book, supported by extensive and meticulous research with supporting bibliography. At the end of the book, there are research notes for each chapter, with additional information and these alone make interesting reading. A selection of photos of places and buildings relevant to the text are fascinating. The structure of the narrative with notes at the end means the flow of the main text isn’t interrupted.

This is a real slice of social history, crossing from the Victorian and into the Edwardian era. It’s not only the story of Henry Slater, arguably Britain’s most successful private detective, it’s a story of the courts and judicial system. It reads like an adventure. How had one man built a large and successful business ended up on the other side of the law? Dr Nell Darby gives a unique and detailed insight into not only the world of private investigation, but into attitudes and society at that time. Women had their place and it was very much a male dominated world. Slater was a first class publicist and knew how to capitalise on success to build a reputation. But his fall from Grace is equally exciting and I’ve enjoyed every page of this cracking title. Creates a real sense of time, place and people.

This book is hands-down a great book that I couldn't put down. Dr Nell Darby has created a wonderful masterpiece that I look forward to sharing with my own audience on my blog. I enjoyed the suspense and mystery that was written keeping me on my toes at all times. This book really puts detective work into a new light as he describes the life Henry Slater. If you are a fan of mystery and historical fiction, then this book is for you.

I read straight through this book in one day. Although non- fiction it reads like the best of novels. The tale of Henry Slater (?) was a fascinating one . His life was laid bare due to a divorce case he and his company were working on and the fallout was catastrophic for his business and reputation. Fuelled by gossip and the press it really mirrors todays exposes.

This book does what is sets out to do - gives the reader an entree into the world of the early private detectives, the people drawn to this type of work, the methods used, and the cases they were typically involved in. Anchoring this tome is the character of Henry Slater - the self proclaimed "greatest detective" of his time.

Darby notes that it was with the passing of the Matrimonial Causes Act 1857 that gave rise to the private detective as courts required evidence of matrimonial misdeeds in order to grant a divorce. This was primarily the type of work available for the private detective, especially one with no connection to the police department.

It is against this that Darby focuses on the case that brought down Slater and his agency - the Pollard divorce case - and highlighted the underhanded dealings that went on to secure the evidence (ie: honey trap, payment of witnesses). None of this would have come to light had Slater not spurned the friendship of one of his employees - Francis Stevens - ".. a man who would do anything to get revenge ..." - including setting up a rival agency and using others to bring about Slater's downfall.

The proceeding court case against Slater and his employees is followed in detail, always referring back to the original Pollard divorce case and methodology used in gaining the required evidence.

Darby follows through to not only the conclusion of the case against Slater et al, but also what followed afterwards for the main players in this drama. Did they get off or were all incarcerated? What happened to the Pollards?

At times the construction of the narrative was a little annoying as it tended to go back and forward in the timeline, but overall it was quite easy to follow. The research that went into this tome is very evident, a times a little dry but never uninteresting.

Definitely one for those interested in the detective agencies that were the UK equivalent of Pinkertons in the 19th and 20th centuries.

This is a fascinating book, well-written and thoroughly researched. It is about a real private detective, yet at times it reads like a novel. In addition to telling the story of Henry Slater, this book discusses identity in Victorian society including class and gender. Even the parts of the book that feel slower are interesting in painting a portrait of Slater and the society in which he lived. I was totally engrossed, even while I was appalled by some of the actions that were pertinent to the trial. Fans of historical true crime (that doesn't involve murder) and Sherlock Holmes will likely find this book interesting.

Thank you to NetGalley and Pen & Sword for the free eARC! I post this review with my honest opinions.

This review is cross-posted on Goodreads, and will be posted on Amazon and Instagram upon the book's publication.