The Bow Street Runners were London's first professional constables. They were founded in 1750 by the novelist and magistrate Henry Fielding and originally numbered just eight.

They worked out of Fielding's office and court at No.4 Bow Street, and did not patrol but served writs and arrested offenders on the authority of the magistrates, travelling nationwide to apprehend criminals. At first they were nicknamed Robin Redbreasts, because their uniform included a scarlet waistcoat.

When Henry Fielding retired in 1754 he was succeeded by his brother John Fielding (known as the "Blind Beak of Bow Street"), who refined the patrol into first truly effective police force for the capital.