The Janamsakhi literature as such relates exclusively to the life and teachings of Guru Nanak, the founder of Sikhism. The spectrum of this genre of literature has several strands. It elucidates mystic concepts of spiritual elevation, provides the earliest exegesis of the hymns of Guru Nanak; and illustrates the teachings of Guru Nanak by narrating interesting anecdotes. The most significant aspect of the Janamsakhi literature is that it has preserved the tradition of Guru Nanak’s life that become the primary source of information for all the writings on Guru Nanak. Of late the historical validity of this material has been called to question in the name of methodology. The author analyses the Janamsakhi material extensively and deciphers the historical contents in this tradition. He concludes that the Janamsakhi shall ever remain the most important source of information on Guru Nanak, if these are studied carefully and intensively.