Long before Sherlock Holmes picked up a magnifying glass, before Hercule Poirot started studying suspects, and before the word “detective” was commonplace, people were already being paid to find criminals.

So who was the first actual detective?

The strongest single answer is Eugène-François Vidocq, a French former criminal, prison escapee, police informant, investigator, and eventually the founder of what is widely described as the first known private detective agency.

But the history is more interesting than one neat name. London’s Bow Street Runners were doing recognisable detective work decades before Vidocq. Vidocq’s importance is that he helped turn detection into something much closer to a distinct modern profession.

Before detectives had a name

In eighteenth-century London, the Bow Street Runners investigated crimes, gathered information, pursued suspects, made arrests, and brought evidence to court. Henry Fielding organised the group in 1749, and his half-brother John Fielding developed it further.

Their work would look familiar to a modern reader. They followed leads, built knowledge of repeat offenders, and learned which people and places mattered. The label did not yet exist in its later sense, but the job certainly did.

That is why the question needs a little care. The detective was not invented by one person on one day. It emerged gradually from constables, magistrates, watchmen, thief-takers, and specialist investigators.

The criminal who became an investigator

Vidocq was born in Arras, France, in 1775. His early life was not the usual route into public service. He spent years around the criminal world, was repeatedly imprisoned, and escaped custody more than once.

In 1809, he began working as an informant for the Paris police. That past gave him an advantage conventional officers did not always have: he understood the language, habits, hiding places, and networks of the people police wanted to find.

This is not a simple redemption story. Vidocq’s career remained controversial, and many accounts of his exploits have been enlarged by memoirs and later retellings. Still, the underlying change is clear. He brought insider knowledge into organised criminal investigation.

The Sûreté and a new kind of police work

By 1813, Vidocq had established a formal plainclothes force associated with the Sûreté. Its agents used informants, surveillance, disguises, undercover work, and records about known offenders. Some had criminal backgrounds themselves.

Those methods were controversial. Employing former offenders to catch offenders could look like a recipe for corruption as easily as a route to better intelligence. Yet the idea behind it was powerful: if crime operates through relationships and local knowledge, an investigation needs more than a uniform and a warrant.

Vidocq did not invent every technique later attached to his name. Claims that make him the sole inventor of forensic science are too broad. His more durable legacy is the combination of intelligence gathering, record keeping, plainclothes investigation, and specialised criminal inquiry.

The first known private detective agency

After leaving official police work, Vidocq opened the *Bureau des Renseignements*, or Office of Information, in 1833. It served private clients and businesses rather than the state. Its surviving correspondence includes requests involving fraud, theft, debtors, and inquiries to officials in France and abroad.

Indiana University’s Lilly Library describes the business as the first known detective agency. That makes Vidocq an unusually strong answer to a narrower question: who founded the first private detective agency?

The agency was eventually suppressed after disputes with the authorities, but the model endured. A person or business could hire a specialist investigator to follow a trail that ordinary policing might not pursue. That is recognisably the private detective of later fiction and film.

What about the Bow Street Runners?

They remain essential to the answer. The Runners were investigating crime more than sixty years before Vidocq’s Sûreté became formalised. They are among the earliest organised crime investigators in England and show that detective work predated the professional title.

London’s Metropolitan Police did not create an official Detective Branch until 1842. By 1878, that branch had become the Criminal Investigation Department, or CID. The modern detective was becoming an institution rather than a loose collection of people with investigative experience.

Question Best answer
Who were early organised crime investigators? The Bow Street Runners
Who is closely associated with a dedicated modern investigation bureau? Eugène-François Vidocq
Who founded the first known private detective agency? Eugène-François Vidocq
When did London create a Detective Branch? 1842
Who is the first major fictional detective? C. Auguste Dupin, created by Edgar Allan Poe

From real investigators to detective fiction

Vidocq’s memoirs began appearing in 1828, and his public reputation soon became almost as dramatic as a novel. His life influenced writers including Honoré de Balzac. In 1841, Edgar Allan Poe introduced C. Auguste Dupin in *The Murders in the Rue Morgue*, a foundational detective story built around reasoning rather than force.

The line from Vidocq to Sherlock Holmes is not perfectly straight, but it is easy to see why his story lodged in the imagination: a criminal becomes an informant, an informant becomes an investigator, and an investigator becomes a legend. That is the kind of biography detective fiction loves.

So who was the world’s first detective?

There is no perfectly clean answer. In 1750, Bow Street officers were already doing work we would call detection. But if the question means the person most closely associated with specialised criminal investigation and the first known private detective agency, Vidocq is the strongest candidate.

The archetype did not begin with Sherlock Holmes. It began, at least in part, with a man Holmes might first have treated as a suspect.

Sources and further reading