The epic poem's age is unknowable, as it was transmitted orally without being recorded. However, historians have doubted the age claimed for it since the turn of the 20th century. The primary reason is that the events portrayed occurred in the 16th and 17th centuries. Central Asian historian V. V. Bartol'd referred to Manas as an "absurd gallimaufry of pseudo-history," and Hatto remarks that Manas was "compiled to glorify the Sufi sheikhs of Shirkent and Kasan ... circumstances make it highly probable that... [Manas is a late eighteenth-century interpolation."