In 1804, Karl Faber (1773–1853) found in the Secret Archive in Königsberg a manuscript containing accounts of the homage paid to the Polish King Sigismund I Jagiellon by the last Grand Master of the Teutonic Knights, Albrecht, in the Krakow main square on April 10, 1525, and published it in print in 1810. The second part of the manuscript was a report on the ceremony of paying homage to Sigismund Augustus by the son of Duke Albrecht, Duke Albrecht Frederick on July 19, 1569 in Lublin. These manuscripts were not used in Polish historiography. For Polish researchers, the basic source containing a description of the Prussian homage from 1525 was an extensive letter from Andrzej Krzycki, the bishop of Przemyśl, who participated in this ceremony, to Pulleon, the papal legate in Hungary, published in volume VII of „Acta Tomiciana” in 1857 in Kórnik.