Key

This steel key, engraved ‘V R HP Pleasure Gardens No 129’ on one side and ‘Sir George Cayley 20 Hertford Street Not Transferable’ on the other, opened one of the privately licensed gates leading from Mayfair into the Hyde Park Pleasure Garden - a fenced-off area on the eastern edge of Hyde Park reserved for a small number of neighbouring households. Private gates could only be created with explicit royal permission; no new entrances were authorised after 1804, but the Office of Works continued issuing numbered, non-transferable keys for the existing gates into the mid-19th century.

The key was held by Sir George Cayley 6th Baronet (1773–1857), the Yorkshire landowner, scientist and pioneering aeronautical engineer often described as the 'father of aviation'. In 1853 he made history when he flew the world's first human-carrying glider across Brompton Dale. Cayley maintained a London residence at 20 Hertford Street, and his possession of a Pleasure Garden key marks him among the select Mayfair households with regulated, private access to this enclosed section of the royal park.

The Pleasure Garden has long since disappeared as a defined space, but keys like this capture a brief period when the boundaries of Hyde Park included private doorways used by only a privileged few.