The janamsakhis are the traditional life-accounts of Guru Nanak Dev Ji. The main traditions are the Puratan, the Miharban, the Bala and the Adi Sakhis, and they disagree with each other on route, chronology and episode.
The Puratan tradition, of which the Colebrooke and Hafizabad manuscripts are the main witnesses, is generally treated as the earliest and most restrained. The Bala tradition is the most widely circulated and the least reliable. The Miharban tradition comes from the rival Mina line and was for that reason ignored by the mainstream for centuries despite being early.
They are not biographies in the modern sense. They are collections of episodes built around a hymn, each one setting up the circumstances in which a composition was given.
They are also the richest source we have on sixteenth and seventeenth-century Punjabi village life, because the settings are drawn from what the tellers knew: the trades, the food, the roads, the money, the manners.
W.H. McLeod's critical work on them in the 1960s and 1970s applied historical method to the tradition and caused a long controversy in Sikh scholarship that has not fully settled.
The Colebrooke manuscript was taken to London in the early nineteenth century and returned to India in 1970 after a long campaign. It is now at Guru Nanak Dev University at Amritsar.
They differ from each other substantially, in the episodes they carry and in the order and geography of the travels, and they were written down long after the events.
They are the tradition's memory rather than its record, and they are also the earliest sustained Punjabi prose. Their literary importance is independent of their historical reliability.