City of London in Greater London, England, United Kingdom — Northwestern Europe (the British Isles)

General Letter Office

Photographed by Andrew Ruppenstein, April 25, 2026

1. General Letter Office Marker

The circle at the end of the text depicts the world’s first postmark, with the “AP” denoting April, and “19” for the date.

Inscription.
Near this spot the General Letter Office stood in Post House Yard 1653-1666

Here were struck in 1661 the first postmarks in the world

Erected by Corporation of the City of London.

Topics and series. This historical marker is listed in this topic list: Communications. In addition, it is included in the UK, England, City of London Corporation series list. A significant historical date for this entry is April 19, 1661.

Location. 51° 30.817′ N, 0° 5.352′ W. Marker is in City of London, England, in Greater London. It is at the intersection of Princes Street and Threadneedle Street, on the right when traveling south on Princes Street. Touch for map. Marker is at or near this postal address: 1 Princes Street, City of London, England EC4N 8BH, United Kingdom. Touch for directions.

Regionally, this marker is in the Greater South East.

Globally, it is on the Atlantic Ocean,

in the North Atlantic Region,

in Europe,

in Atlantic Europe,

on one of the British Isles,

in the Western World,

and in the Anglosphere.

Historically, it finds itself in what was once the Roman Empire.

Other nearby markers. At least 8 other markers

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are within walking distance of this marker: Elizabeth Fry (within shouting distance of this marker); Stocks Market (within shouting distance of this marker); St Mildred’s Church (within shouting distance of this marker); St Mary Woolchurch (within shouting distance of this marker); Wellington (within shouting distance of this marker); Royal Exchange Jubilee Walkway (within shouting distance of this marker); Royal Exchange Forecourt (within shouting distance of this marker); Thomas Hood (within shouting distance of this marker). Touch for a list and map of all markers in City of London.

Also see . . . Henry Bishop (postmaster general) (Wikipedia). Excerpt:

Henry Bishop introduced the world's first known postmark in London in 1661. The "Bishop Mark" was designed to show the date on which a letter was received by the post and to ensure that the dispatch of letters would not be delayed. These were the world's first handstruck postage stamps.

The original London Bishop Mark, first used 19 April 1661. The earliest known examples of use are in the Public Records Office, Kew, West London, consisted of a small circle of 13 mm
Photographed by Andrew Ruppenstein, April 25, 2026

2. General Letter Office Marker - wide view
diameter, bisected horizontally, with the month (in serifed lettering) abbreviated to two letters, in the upper half and the day of the month in the lower half. Similar marks were used later in Scotland and Ireland, as well as the North American colonies.

(Submitted on April 26, 2026, by Andrew Ruppenstein of Lamorinda, California.)

Additional keywords. blue plaque

Credits. This page was last revised on April 26, 2026. It was originally submitted on April 26, 2026, by Andrew Ruppenstein of Lamorinda, California. This page has been viewed 11 times since then. Photos: 1, 2. submitted on April 26, 2026, by Andrew Ruppenstein of Lamorinda, California.