North out of High Holborn to King's Cross (P.O. Directory).
First mention: O.S. 1875.
Former names : "Grays Inn Lane" (O.S. 1848-51). "Graysynlane," otherwise "Portpole Lane," 1468 (Ct. H.W. II. 561). "Grayesynne lane," 1549 (ib. 670).
In later times in the maps Portpool Lane is not identified with Gray's Inn Lane, but is represented as at right angles to it, and the name was probably transferred from one street to the other.
Named after Gray's Inn.
A Dictionary of London. Henry A Harben. 1918.