History of the Metropolitan Police
Great Scotland Yard
This was a small street running east from the northern end of Whitehall, parallel with Whitehall Place. The original Metropolitan Police Commissioner's office (No. 4 Whitehall Place) backed on to it, and A Division was based there in the back of the building. The name became colloquially attached to the headquarters of the Metropolitan Police, especially as additional buildings were acquired to house branches of the expanding force.
The exact origin of the name is unclear. The following two stories have both gained creedance at various times:
It is said the location had been the site of a residence owned by the Kings of Scotland before the Union and used and occupied by them and/or their ambassadors when in London, and known as '"Scotland". The courtyard was later used by Sir Christopher Wren and known as "Scotland Yard".
The street names are said to have derived from the land being owned by a man called Scott during the Middle Ages.