West out of Whitefriars Street, at No. 20, to George Yard, within the precinct of Whitefriars, in Farringdon Ward Without (P.O. Directory).
First mention: In P. Clerks, 1732, described as "Magpye alley," or "glasshouse alley" in Great Ashentree Court."
In Lockie, 1816, at the north end of Glasshouse Alley.
A Dictionary of London. Henry A Harben. 1918.