ENUntil now, the dominant view in historiography has been that Grand Duke Algirdas of Lithuania had four types of seals. One depicted a knight, while the others had forms of crossed arrows-either widened with a rombus shape in the middle or with a cross covering connected arrows. Examination of historical data and archival materials revealed that three of the four seals attributed to Lithuanian Grand Duke Algirdas in reality have no link to him. The “oldest seal” of Algirdas (dated either 1337 or 1342) did not in fact belong to Algirdas but to his great-grandson Grand Duke Alexander. The seal with arrows, which was placed on the agreement between Lithuania and Moscow to cease fighting, did not represent the Lithuanian ruler but most likely his brother-in-law Duke Boris Konstantinovich. The seal mentioned by Marian Gumowski was created by the author himself from the seal of Duke David Dmitriyevich, who was a vassal of Algirdas’s son Kaributas. There is not a single seal of Algirdas that features linked arrows. Tadeusz Czacki’s data about a seal of Algirdas with a knight is also very suspect. Whether the honorable historian Czacki did see such a seal can only be checked by additional testing of the material of the copies of the 1366 agreement and other.