Milarepa is generally placed in eleventh and early twelfth century Tibet, but the biography that made him famous, commonly called the Life of Milarepa and attributed to Tsangnyon Heruka, was composed some three hundred years later. It belongs to the Tibetan namtar or liberation story genre, a form built to teach the path to awakening through a life, not to record one the way a chronicle would. The most quoted episodes, the killing carried out through black magic at his mother's urging, the punishing trials his guru Marpa set him, building and then demolishing stone towers before agreeing to teach him, are the narrative spine of that purpose: they dramatize the working out and exhaustion of severe karma within a single lifetime.
Because the detailed account is a much later literary composition rather than a contemporary record, scholars treat the specific incidents as teaching material shaped by the genre's conventions rather than verified biography, while treating Milarepa's existence, his discipleship under Marpa, and his standing as a poet and founding figure of the Kagyu lineage as reasonably secure. The songs collected as the Hundred Thousand Songs of Milarepa were likewise gathered and arranged after his lifetime, so the received portrait of the man is inseparable from the tradition that formed around him in the centuries following his death.