Although the history of monied policing in London extends back to the world of the 16th century informer, spy, and thief- taker and includes entrepreneurs such as Mary Frith and Jonathan Wild, this article focuses on monied policing in the mid-18th century. It begins by examining the political economy of monied policing, showing how money and law came to define the nature of police work in the metropolis. Next, the author analyses the reform initiatives of Henry Fielding, Saunders Welch, and Sir John Fielding. The article addresses two related questions: Did their policing reforms contribute to the commodification of policing services in and around the city? How successful were the "new improved monied police" in creating a new criminal investigation and surveillance apparatus for London? The article concludes by examining the aftermath of reform on commercial policing. Topics considered are the roles of buyers and sellers in the policing market-place change, who had market dominance, who had administrative control, and the social implications of monied policing for security and protection in the metropolis. 78 references