Although Lady Penelope and Parker were among the first characters to be developed, neither was conceived as a central character. The inspiration for Parker came from director David Elliott, who had been reading a spy novel about a safecracker who unwittingly becomes a government agent. The character's Cockney speech (dubbed "Parkerese" by Graham and series creator Gerry Anderson) was based on the voice of a wine waiter at the Kings Arms in Cookham, Berkshire, which was regularly visited by members of the crew. Anderson said that Arthur, who was once in the service of Elizabeth II at Windsor Castle, spoke with a "warm patter, dropping his 'aitches' and putting them back in the wrong places, and this intrigued me ... I thought voice would be perfect." He therefore had Graham dine at the establishment to learn the style. Anderson did not inform Arthur of his contribution to Parker's characterisation, worried that he would dislike the public recognition that it might bring if it became widely known.