[[File:Kazimierz Wielki - kamienica hetmańska.jpg|thumb|upright|left|A supposed portrait of Casimir the Great (2nd half of the 14th century) on a bossed keystone at the Hetman House (below one of the Wierzynek restaurant's dining rooms) in Cracow]]
The only historical source that mentions the banquet at Wierzynek's are the ''Annals of the Glorious Kingdom of Poland'' by Jan Długosz, also known by his Latinized name, Joannes Longinus. According to his account, the whole story started when Charles of Luxembourg, emperor of the Holy Roman Empire and king of Bohemia (a region kingdom roughly corresponding to the modern-day Czech Republic), spoke offensively, in the presence of Hungarian was receiving envoys, of their from Hungary and said something very offensive about King Louis the Greatof Hungary's mother (which, I suppose, means the he simply called Louis a son of a whore)mom. It led, obviously, to a major diplomatic crisis. Louis, together with Duke Rudolph Habsburg of Austria (who also had his differences with his the emperor and , incidentally, his father-in-law), was getting ready to go to for war. This is when Pope Urban V decided it was enough that Western Europe, recently ravaged by a pandemic of bubonic plague, was already being plunged into a bloody conflict (which would later come to be knows known as the Hundred Years' War). Having rulers of the relatively stable and quickly developing Central Europe at each other's throats would be too much. This Which is why he dispatched his nuncio, Peter of Volterra, to try and calm them down. The nuncio did a great job -- he managed to prevent hostilities and to convince the wrangling monarchs to settle their argument through arbitration. It was agreed there would be two adjudicators: one was Duke Bolko the Small of Schweidnitz, the last sovereign ruler in Silesia and uncle of the emperor's recently deceased third wife. The other was King Casimir of Poland, brother of the Hungarian queen mother whose honour had been besmirched.
The nuncio also engaged in matchmaking and arranged the marriage of the recently widowed emperor with Casimir's granddaughter, Duchess Elizabeth of Stolp, Pomerania. The wedding was held in Cracow. According to Longinus, people invited by King Casimir included -- apart from the young bride (and her family) and the not-so-young groom (and his family) -- King Louis of Hungary, King Sigismund of Denmark, King Peter of Cyprus, Duke Bolko the Smallof Schweidnitz, Duke Otto V of Bavaria, Duke Semovit of Masovia, Duke Vladislav II of Opole etc. The wedding reception lasted twenty days, during which barrels of wine were put out in the streets for the common folk, while the royals and lords enjoyed tournaments, dances and banquets. The festivites were overseen -- again, according to Longinus -- by a certain Wierzynek, "a councillor of Cracow, native of the Rhineland" and "manager of the royal treasury". He held one of the banquets in his own home, where -- in gratitude for "unspeakable benevolence" -- he seated King Casimir (and not the emperor!) in the place of honour and showered him with presents that were worth more than the new empress's dowry.<ref>{{Cyt
| nazwisko = Długosz
| imię = Jan