History of the Metropolitan Police

Origins of the name "Old Bill"

We are often asked about the origins of "The Old Bill" or "The Bill" as slang names for the police. The simple answer is that no one really knows for sure. Over the years at least 13 different possibilities have been proposed, as follows:

1. "Old Bill" was King William IV, whose constables were an early form of police. (It is often said erroneously that he was on the throne when the police were founded. Actually he did not succeed George IV until 1830)
2. The play "The Custom of the Country" written by John Fletcher in 1619 has constables of the watch refer to themselves as 'us peacemakers and all our bill of authority'.
3. Constables of the watch were sometimes nicknamed for the bills, or billhooks they carried as weapons.
4. Kaiser Wilhelm I of Prussia visited England around the time in 1864 when the police uniform changed from top hat and swallowtail coat to helmet and tunic. Such 'Prussian militarism' may have led to the police being nicknamed after the first (and today less remembered) Kaiser Bill.
5. The 'old bill' was, in Victorian times, a bill presumed to be presented by the police for a bribe to persuade them to turn a blind eye to some nefarious activity.
6. New laws for the police to enforce all come from bills passed through Parliament
7. "Old Bill" might refer to Bill Bailey of the music hall song 'Won't You Come Home...?' used in conjunction with a pun on the Central Criminal Court at the Old Bailey.
8. In the 1860s there was a Sergeant Bill Smith in Limehouse. He was a popular character and people used to ask after 'Old Bill'.
9. Many police officers wore authoritarian-looking "Old Bill" moustaches like that adorning a famous W.W.1 cartoon character 'the wily old soldier in the trenches' by Bruce Bairnsfather.
10. In 1917 the government used Bairnsfather's character in posters and advertisements putting over wartime messages under the heading "Old Bill says...". For this campaign the character was dressed in a special constable's uniform.
11. The original vehicles used by the Flying Squad all had the registration letters BYL, so the squad became known as 'the Bill'.
12. The London County Council at one time registered all police, fire and ambulance vehicles with the letters BYL
13. According to old Etonian illegal gaming club organizer and author the late Robin Cook ('Derek Raymond'), 'old bill' is a racing term for an outsider or unknown quantity. From the point of view of the underworld, police would be outsiders

Despite all these suggestions, the earliest documented usage traced by the Metropolitan Police Historical Museum is from 1970 and 'Partridge's Dictionary of Slang'. Without giving citations the book dates "Old Bill" from the 1950s "or perhaps earlier". So the term may possibly be post W.W.2.