The present card was engraved by Pemberton of 100 Long Acre, who appears to have been active during the final fifteen years of the eighteenth century, in which time he engraved trade cards for several of London's merchants and servicemen. These dates show that "their majestys" must refer to King George III and his wife, Queen Charlotte, who met for the first time on their wedding day in the Chapel Royal at St James's Palace. Although the most senior royal palace, George III did not like St. James's, finding the Tudor building too uncomfortable and accessible to the public. In 1762, therefore, he purchased Buckingham House, which would later become Buckingham Palace, to be their family home. In 1809, a fire destroyed much of the palace including the monarch's private quarters, which George did not bother to replace when he commissioned large refurbishments.

Overall, during the reign of George III, St James's Palace was used only on formal occasions, such as the levées and public audiences that occurred three times a week. It is presumably for such occasions that marshals were required "to regulate & call up the Coaches and Servants and conduct the Chairs &c". The "six marshal men" named on the present card were probably charged with a range of logistical and organizational tasks at times when large groups or crowds were expected at the palace.

The precise nature of the card is not immediately apparent. It may be a shared trade card advertising their services as marshals, but it is more likely to serve as some form of identification, perhaps an early example of a security pass. Being in possession of such a card showing one's name, may have granted access to certain areas of the palace. The manuscript note that runs along the lower edge suggests that it may have allowed the marshal to enter "likewise at the House of Lords". The card is surmounted by the royal crest, and also has an illustration of a portcullis. The portcullis began to be used as a symbol of the Palace and Parliament during the mid-nineteenth century, but it was widely used as a motif in royal architecture for many centuries prior.