Historical Dictionary of London

OLD GENERAL POST OFFICE

On the east side of St. Martin le Grand (Street), between that street and Foster Lane.
Erected 1825-9. Archt., Sir Robt. Smirke.
Other buildings were erected subsequently on the west side of St. Martin's le Grand, for the Telegraph Office, removed there from Telegraph Street 1873.
The Post Office was erected on what had formerly been the site of the old collegiate foundation of St. Martin's le Grand, a site subsequently covered by numerous small courts, etc., such as Dean's Court, George Street, Round Court, Mouldmaker's Row, New Rents, Bell Square, Bell Court, all removed for the erection of the Post Office buildings.
The buildings on the east side of St. Martin's le Grand were closed in 1910 (when the new buildings in King Edward Street were completed), and they have since been taken down.
The buildings on the west side are still in use for the purposes of the Post Office.