In the archives of the Franciscan province in Krakow we found twenty-eight unpublished letters of Saint Maksymilian Kolbe (ref. no. F-II-4), which were written between October 19, 1919 and June 25, 1938. Most of them are letters addressed to priest Bronisław Stryczny (1892—1974), a great friend of Father Maksymilian. This friendship dates back to the times of the novitiate in Lviv, where, thanks to the decision of the novitiate master, Stryk helped Maksymilian Kolbe overcome his scruples. The letters are testimony to the friendship that later united these two religious people. Maksymilian found understanding and comfort in his friend, and he turned to him again for help when the construction of the Niepokalanów complex began. The letter of May 7, 1924 is important because it reveals Maksymilian's involvement in the reformist movement, which he had long supported in the Polish Franciscan province. The currently published letters will undoubtedly contribute to a better understanding of the work and thoughts of the Auschwitz martyr.