On 7 October 1551, Sir Thomas Palmer came to visit the Earl of Warwick in his garden to deliver “a very fair” gold chain, a chain of office which went with the rank of duke. For only four days later John Dudley, Earl of Warwick, was to become the Duke of Northumberland. “Wherupon,” Palmer, “in my lord’s gardein he declared a conspiracye.” Part of this conspiracy was “a devise … to call th’erl of Warwike to a banket, with the marq[uess] of Northampton and divers other, and to cutte of there heades.”

The Historie of Italie by William Thomas was dedicated to John Dudley, Earl of Warwick, in 1549
This is how the 14-year-old King Edward VI described it in his journal. The banquet massacre was to take place in Lord Paget’s house. Although the Duke of Somerset (the king’s uncle and former Protector of England) did engage in quite a bit of plotting against his de facto successor in government, John Dudley, Earl of Warwick, there can be no doubt that either Palmer or possibly even Warwick himself invented the supposed banquet massacre. Certainly, before any banquet took place, Somerset was arrested and placed in the Tower of London, and beheaded a few months later.
There had occurred real banquet massacres in Italy, however. The author and literary critic John Addington Symonds wrote in his book Renaissance in Italy: “In 1446 the Canetoli, powerful nobles, who hated the popular dynasty, invited Annibale and all his clan to a christening feast, where they exterminated every member of the reigning house. Not one Bentivoglio was left alive.”
Symonds has more: “It is worthy of notice that very many tyrannicides took place in Church—for example, the murders of Francesco Vico dei Prefetti, of the Varani, the Chiavelli, Giuliano de’ Medici, and Galeazzo Maria Sforza. The choice of public service, as the best occasion for the commission of these crimes, points to the guarded watchfulness maintained by tyrants in their palaces and on the streets. Banquets and festivities offered another kind of opportunity; and it was on such occasions that domestic tragedies, like Oliverotto [da Fermo]’s murder of his uncle and Grifonetto Baglioni’s treason, were accomplished.”
John Dudley, Earl of Warwick, in 1549 had been the dedicatee of William Thomas’ The Historie of Italie. While this book was a rather dry account, Thomas had travelled in Italy himself, staying there for five years, and it is likely that he would have used earlier accounts by Italian historians (such as the chronicles of Giovanni and Matteo Villani, as well as Bernardino Corio) for his own work. (William Thomas also wrote a book on Henry VIII after the king’s death in which he praised all his acts.) It is possible that John Dudley’s circle, to which belonged not just Thomas Palmer, a soldier with an axe to grind with Somerset, but also William Thomas, was well versed in the history of Italy’s courts and tyrannies. At least they would have formed a clichéd opinion of what was typically Italian, like the use of poison, and banquet massacres.
Then there was the Black Dinner of 1440 at Edinburgh Castle: The young Earl of Douglas and his even younger brother (a child) were invited to the court of James II (who was 10) and beheaded after dinner. Perhaps this story was well-known in England, too. Sir Thomas Palmer had served in Somerset’s Scottish wars (where he incidentally made friendship with Master John, an Italian expert on fortifications).
Robert Dudley, in later life, was also very fond of everything Italian; he spoke Italian fluently, and he had close contacts to both members of the London Italian community and visiting Italian adventurers and artists.
Sources:
Literary Remains of King Edward the Sixth (1857)
Christine Hartweg, John Dudley: The Life of Lady Jane Grey’s Father-in-Law (2016)
John Addington Symonds, Renaissance in Italy: The Age of the Despots (1888)
William Thomas, The History of Italy (1549) (1963)
Did you see “Who do you think you are?” about the journalist Frank Gardner, whose ancestor was arrested and beheaded with Somerset?
Sorry, collateral descendant:
https://murreyandblue.wordpress.com/2016/04/09/a-tudor-marriage-and-a-contemporary-journalist-who-is-the-brides-collateral-descendant/
Wow
I added the story of the Black Dinner, which came to my mind this morning.
Beware the Black Douglases! You wouldn’t accept an invitation to a banquet from James Douglas, Earl of Morton, who allegedly poisoned the earls of Mar and Atholl (at different times). However, he got his just desserts being beheaded on his Maiden.
This man? How interesting! https://en.wikipedia.org/wiki/James_Douglas,_4th_Earl_of_Morton