E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
When Thomas Cromwell was a clerk in the English factory at Antwerp, two of his fellow-countrymen from Boston (Lincolnshire) consulted with him as to the best means of getting the pardons renewed for the repair of Boston harbour. Cromwell, knowing that Pope Julius was very fond of dainties, provided for him some exquisite jelly, and told his Holiness that only royalty ever ate it in England. The Pope was so pleased with the delicacy that he signed the pardons, on condition of having the recipe of the jelly.