Alsatia in London, was the name given to an area lying north of the River Thames covered by the Whitefriars monastery, to the south of the west end of Fleet Street and adjacent to the Temple. Between the fifteenth and seventeenth centuries it had the privilege of a sanctuary, except against a writ of the Lord Chief Justice or of the Lords of the Privy Council; and as a result it was the refuge of the perpetrators of every grade of crime, debauchery, and offence against the laws. The execution of a warrant there, if at any time practicable, was attended with great danger, as all united in a maintenance in common of the immunity of the place. It was one of the last places of sanctuary used in England, abolished by Act of Parliament named The Escape from Prison Act in 1697 and a further Act in 1723. Eleven other places in London were named in the Acts (The Minories, The Mint, Salisbury Court, Whitefriars, Fulwoods Rents, Mitre Court, Baldwins Gardens, The Savoy, The Clink, Deadmans Place, Montague Close, and Stepney).
Alsatia was named after the ancient name for Alsace, Europe, which was itself outside legislative and juridical lines, and, therefore, they were literally places without law. The name is thought to be a cant term for the area and is first known in print in the title of The Squire of Alsatia, a 1688 play written by Thomas Shadwell.
The name was used into the 20th century as a term for a ramshackle marketplace, "protected by ancient custom and the independence of their patrons".
As of 2007, the word is still in use among the English judiciary with the meaning of a place where the law cannot reach: "In setting up the Serious Organised Crime Agency, the state has set out to create an Alsatia - a region of executive action free of judicial oversight," Lord Justice Sedley in UMBS v SOCA 2007.