The postal service in Britain dates back to the establishment of the Royal Mail by Henry VIII in 1516. However, it wasn't until 1852 that the first post boxes were introduced.

The initial post boxes were first seen in the Channel Islands, and their introduction is credited to Anthony Trollope, a postal surveyor who later became a famous novelist. The first mainland boxes appeared in 1853 in Carlisle, Lancashire, and the West Country.

Initially, post boxes were designed in various shapes, but by the 1860s, the classic pillar box design, which is still in use today, was adopted. The familiar red colour was chosen to ensure visibility (earlier boxes were painted green). In the late 19th century, wall boxes and lamp boxes (smaller boxes attached to lamp posts or walls) were introduced to provide more convenient posting options. After World War II, new designs, including rectangular boxes with larger apertures to handle increased mail volume, were introduced. Notable among these are the K-type pillar boxes, introduced in 1979.

A key feature of the post box is the royal cypher, a monogram representing the reigning monarch, indicating during whose reign the post box was installed. Royal cyphers were first used on post boxes with the introduction of the pillar box in the 1850s. Here is a list of royal cyphers:
  • Queen Victoria (1837-1901) - "VR" (Victoria Regina)
  • Edward VII (1901-1910) - "E VII R" (Edward VII Rex)
  • George V (1910-1936) - "GR" (George Rex)
  • Edward VIII (1936) - "E VIII R" (Edward VIII Rex)
  • George VI (1936-1952) - "G VI R" (George VI Rex)
  • Elizabeth II (1952-2022) - "E II R" (Elizabeth II Regina)
  • Charles III (2022-present) - new post boxes will feature the "C III R" monogram for Charles III Rex.

www.postalmuseum.org

More than 60% of current British post boxes carry the mark of Queen Elizabeth II or a Scottish crown. Boxes from George V's reign make up about 15%, with smaller numbers from the reigns of George VI, Victoria, and Edward VII.

The rarest royal cypher is that of Edward VIII, who was king for less than a year, from 20th January 1936 until his abdication on 11th December 1936. His reign is one of the shortest in British history. The Letter Box Study Group has identified 171 boxes surviving from his reign, three of which are said to be in Sheffield (after a bit of research).

The one we found today is located at the junction of Carter Knowle Road and Button Hill (S11).