The person of the 13th-century Dominican, Marcin Polak, a famous historiographer, and his most important works: "The Chronicle of Popes and Emperors" and "The Pearl of the Decree" - are poorly known today and, in a sense, especially in Polish literature, forgotten. The lack of sufficient source information makes it very difficult to establish the basic facts from Marcin's life. The literature that has developed over the centuries around his person and works is also full of misunderstandings, errors and disputes. The work discusses in detail the available archival sources related to the monk and the most important facts from his life and work.