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 Siege of Shkodër (''Rrethimi i Shkodrës'') from 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'') from 1508. The ''History of Skanderbeg'' is still the foundation of Skanderbeg studies and is considered an Albanian cultural treasure, vital to the formation of Albanian national self-consciousness.