I found this entry on the Patent Roll ages ago while searching for something else, and have finally got round to making a post about it. It's intriguing and puzzling!
Calendar of Patent Rolls 1292-1301, p. 459, dated 26 December 1298 (bold mine):
"Commission of oyer and terminer ['to hear and determine'] to Ralph de Sandwyco ['of Sandwich'] and Henry le Galeys ['the Welshman'], on the supplication of the appellees, touching an appeal which Landus Bonacursi of Lucca brings in London against Aldebrandus Malagaile and Berinus Mayamund, merchants of Lucca, for counterfeiting the king's great and privy seal and the seal of Edward the king's son, and for proposing to poison the king and his said son; and they are to hear and determine the appeal in the presence of Henry de Lacy, earl of Lincoln."
Calendar of Patent Rolls 1292-1301, p. 459, dated 26 December 1298 (bold mine):
"Commission of oyer and terminer ['to hear and determine'] to Ralph de Sandwyco ['of Sandwich'] and Henry le Galeys ['the Welshman'], on the supplication of the appellees, touching an appeal which Landus Bonacursi of Lucca brings in London against Aldebrandus Malagaile and Berinus Mayamund, merchants of Lucca, for counterfeiting the king's great and privy seal and the seal of Edward the king's son, and for proposing to poison the king and his said son; and they are to hear and determine the appeal in the presence of Henry de Lacy, earl of Lincoln."
So why exactly were merchants of Lucca in Italy attempting to poison King Edward I and his son Edward of Caernarfon, who was only fourteen at the time, in 1298? Unfortunately I've been unable to find any more information about this curious and rather astonishing plot, or the men involved. Aldebrand(us) Malagal(e) appears on the Patent Roll in 1274 (CPR 1272-81, pp. 52, 54) as one of the merchants given permission by Edward I to trade wool in England, but why he decided nearly a quarter of a century later to poison the king and his son, I cannot imagine.
It's interesting to speculate about the succession to the English throne at the end of the 1200s. Let's say Edward I and his son Edward of Caernarfon had been successfully poisoned in 1298, and they both died. Edward I had not yet married his second wife Marguerite of France - their wedding took place on 8 September 1299 - and the births of their two sons Thomas of Brotherton and Edmund of Woodstock lay in the future, in June 1300 and August 1301. If Edward I died in 1298, his second marriage would never have taken place and Thomas and Edmund would never have existed, and neither would Edmund's daughter and ultimate heir Joan of Kent, her youngest son Richard II and her Holland children (and her eldest son Thomas Holland, died 1397, was the ancestor of basically everyone). Thomas of Brotherton was, via his daughter and heir Margaret (d. 1399), the ancestor of the Mowbrays and the Howards, so two of Henry VIII's wives would never have existed either. Neither would Henry VIII himself, a descendant of Joan of Kent and her son Thomas Holland as well as of Joan's uncle Edward II.
Edward of Caernarfon was Edward I's only living son between August 1284 and June 1300, and he himself, born April 1284, was of course too young to have produced any children by 1298. Edward I's only brother Edmund of Lancaster had died in June 1296, leaving his sons Thomas and Henry of Lancaster, who were about twenty and eighteen in 1298. According to a document Edward I produced in April 1290, however, if his son Edward of Caernarfon died without heirs of his body, the king wished the throne to pass to his eldest surviving daughter Eleanor, later countess of Bar, born in June 1269, rather to his Lancaster brother and nephews. Eleanor herself died in August 1298 four months before this entry about the plot to poison her father and brother appeared on the Patent Roll. She was only twenty-nine when she died, perhaps of complications relating to pregnancy or childbirth (though I'm only speculating). Her heir was her son Edouard, born in 1294 or 1295 and also heir to his father Henri's county of Bar in eastern France, and her only other child was Jeanne, later countess of Surrey, born in 1295 or 1296.
Edward of Caernarfon was Edward I's only living son between August 1284 and June 1300, and he himself, born April 1284, was of course too young to have produced any children by 1298. Edward I's only brother Edmund of Lancaster had died in June 1296, leaving his sons Thomas and Henry of Lancaster, who were about twenty and eighteen in 1298. According to a document Edward I produced in April 1290, however, if his son Edward of Caernarfon died without heirs of his body, the king wished the throne to pass to his eldest surviving daughter Eleanor, later countess of Bar, born in June 1269, rather to his Lancaster brother and nephews. Eleanor herself died in August 1298 four months before this entry about the plot to poison her father and brother appeared on the Patent Roll. She was only twenty-nine when she died, perhaps of complications relating to pregnancy or childbirth (though I'm only speculating). Her heir was her son Edouard, born in 1294 or 1295 and also heir to his father Henri's county of Bar in eastern France, and her only other child was Jeanne, later countess of Surrey, born in 1295 or 1296.
Had Edward I and Edward of Caernarfon died in late 1298, the rightful heir to the English throne was almost certainly a three or four-year-old French boy, Edouard of Bar. A curious and arresting thought. I wonder what would have happened if the would-be poisoners had killed the king and his only son? Would the English magnates have accepted little Edouard of Bar as their king and had him brought to England, or would Thomas of Lancaster, who had the benefit of being an adult and of being an Englishman, have made a bid for the throne? Edward I's only other grandson born by 1298 was Gilbert de Clare, heir to the earldoms of Gloucester and Hertford, born in 1291 as the son of Edward I's second daughter Joan of Acre, and the eldest grandchild of Edward I. Would his mother Joan have promoted the claims of her own child, who also had the advantage of being English, over those of her nephew Edouard of Bar? Joan of Acre was alive and in England, whereas her elder sister Eleanor was not, and Eleanor's widower Henri, count of Bar (d. 1302) had no political influence whatsoever in England. Would Joan have been able to push the claims of her son as King Gilbert over those of her Lancaster cousin as a potential King Thomas, and over those of her young nephew as an alternative King Edouard II?
On the other hand, Thomas of Lancaster had the mighty Lancastrian inheritance behind him, and his influential father-in-law Henry de Lacy, earl of Lincoln (who lived until 1311), might well have promoted his claims to the throne in the interests of seeing his daughter Alice crowned queen of England. Thomas was indisputably a grandson of Henry III (d. 1272) in the male line and equally royal on his mother Blanche of Artois's side, whereas Edward I's grandsons in 1298 were descended from him in the female line (Edward III and his younger brother John of Eltham, not born until 1312 and 1316, were Edward I's only grandsons in the male line). Self-interest might have been a much greater motivator for many powerful Englishmen than seeing a boy little more than a toddler and living in distant Bar-le-Duc crowned as their king, even if he was lawfully the next in line. Perhaps England would have seen civil war between the supporters of the would-be King Thomas versus the supporters of the would-be King Gilbert? And what might Philip IV of France have done? He invaded the county of Bar in 1297 as punishment for Henri III aiding his father-in-law Edward I against him, and in 1301 forced Henri to recognise him as his overlord for a large part of his territories. In 1298/99, might Philip have thought it worth his while to put his differences with Henri aside, and perhaps attempt to have the little Edouard of Bar installed as a client king of England? And if Edward of Caernarfon died in 1298, Philip's daughter Isabella, only about three years old then, would have lost her future husband, and would have had to marry someone else. King Fernando IV of Castile? Duke John III of Brittany? Hugh V or his younger brother Odo IV, dukes of Burgundy?
On the other hand, Thomas of Lancaster had the mighty Lancastrian inheritance behind him, and his influential father-in-law Henry de Lacy, earl of Lincoln (who lived until 1311), might well have promoted his claims to the throne in the interests of seeing his daughter Alice crowned queen of England. Thomas was indisputably a grandson of Henry III (d. 1272) in the male line and equally royal on his mother Blanche of Artois's side, whereas Edward I's grandsons in 1298 were descended from him in the female line (Edward III and his younger brother John of Eltham, not born until 1312 and 1316, were Edward I's only grandsons in the male line). Self-interest might have been a much greater motivator for many powerful Englishmen than seeing a boy little more than a toddler and living in distant Bar-le-Duc crowned as their king, even if he was lawfully the next in line. Perhaps England would have seen civil war between the supporters of the would-be King Thomas versus the supporters of the would-be King Gilbert? And what might Philip IV of France have done? He invaded the county of Bar in 1297 as punishment for Henri III aiding his father-in-law Edward I against him, and in 1301 forced Henri to recognise him as his overlord for a large part of his territories. In 1298/99, might Philip have thought it worth his while to put his differences with Henri aside, and perhaps attempt to have the little Edouard of Bar installed as a client king of England? And if Edward of Caernarfon died in 1298, Philip's daughter Isabella, only about three years old then, would have lost her future husband, and would have had to marry someone else. King Fernando IV of Castile? Duke John III of Brittany? Hugh V or his younger brother Odo IV, dukes of Burgundy?
There are of course no answers to these questions as it's all hypothetical, but I do find it fascinating to speculate, and it's certainly true that for the sixteen years between August 1284, when his elder brother Alfonso of Bayonne died, and June 1300, when his half-brother Thomas of Brotherton was born, Edward of Caernarfon was the sole uncontested male heir to the English throne. His three elder brothers John, Henry and Alfonso all died in childhood, as did at least five of his older sisters, so certainly his father and others must have considered the possibility that he might die as well. Edward I was almost sixty years old at the end of 1298, and surely he and others must have contemplated the possibility that he would die before he fathered any more sons or before Edward of Caernarfon himself fathered any. (And as there were nine years between the death of Eleanor of Castile in 1290 and Edward I's marriage to Marguerite in 1299, he was hardly in a tearing hurry to marry again and father more children, and wed Marguerite as a means to end his war against Philip IV.) I've previously written a post about Edward I and Queen Eleanor escaping from a fire in August 1283, at the start of Queen Eleanor's pregnancy with Edward II (born April 1284), and speculated what might have happened had they both died and their unborn son with them. This is another great what-if, fifteen years later.