Albanian writings from these centuries must not have been religious texts only, but historical chronicles too. They are mentioned by the humanist Marin Barleti, who, in his book "Rrethimi i Shkodrës" (The Siege of Shkodër) (1504), confirms that he leafed through such chronicles written in the language of the people ("in vernacula lingua") as well as his famous biography of Skanderbeg "Historia de vita et gestis Scanderbegi Epirotarum principis" (History of Skanderbeg) (1508). The History of Skanderbeg is still the foundation of Scanderbeg studies, and is considered an Albanian cultural treasure, vital to the formation of Albanian national self-consciousness.