John Calvert was one of England’s finest chess carvers, and his workshop was established in 1791 at 189 Fleet Street, London- at that period one of London’s best addresses for upmarket shops selling luxury goods to the carriage trade. After his death in 1822 (the National Archives hold a ‘declaration of trust under the will of John Calvert, deceased’, dated 1822) his widow, Dorothy, managed the business until her death in 1840.
According to Sir Alan Fersht, only a fraction of Calvert sets were stamped. Many other chess sets, clearly attributable to Calvert due to their style and quality, were left unstamped.
This is a large example (the king is over 4 inches in height) and of a very fine quality.