Milarepa's life-story is famous in the Tibetan culture, and retold many times. The best-known biography, The Life of Milarepa, written by Tsangnyön Heruka [1452–1507] in the fifteenth century and drawing from older biographies, is still very popular. Most of the present-day stories on Milarepa come from this single source, with oral lineage predominating this as well as relics including his bear skinned coat. While "very little [is known] about him as a historical person at all," Milarepa is venerated by all Tibetan schools "as an exemplar of religious dedication and mastery," and his life story established the lineage of the Kagyu sect and its key figures.
According to The Life of Milarepa, Milarepa was born in western Tibet to a prosperous family. When his father died, his family was deprived of their wealth by his aunt and uncle. At his mother's request, Milarepa left home and studied sorcery to take revenge, killing many people. Later he felt sorrow about his deeds, and became student of Marpa the Translator. Before Marpa would teach Milarepa, he had him undergo abuse and trials, such as letting him build and then demolish three towers in turn. Milarepa was asked to build one final multi-story tower by Marpa at Lhodrag, which still stands. Eventually, Marpa accepted him, explaining that the trials were a means to purify Milarepa's negative karma.
Marpa transmitted Tantric initiations and instructions to Milarepa, including tummo ["yogic heat"], the "aural transmissions" [Wylie: snyan rgyud], and mahamudra. Marpa told Milarepa to practice solitary meditation in caves and mountain retreats, which, according to the biography, after many years of practice resulted in "a deep experiential realization about the true nature of reality."In some other sources, it is said that Milarepa and Marpa both came to India to seek one most important thing for ultimate realisation from Marpa's guru ,but even he didn't know about it. Later on he tried for many years and finally attained enlightenment. Thereafter he lived as a fully realized yogi, and eventually even forgave his aunt, who caused the misfortune of his family.
Gampopa was Milarepa’s most renowned student. Four of Gampopa’s students founded the four major branches of the Kagyu lineage: Barom Kagyu, Karma Kagyu, Phagdru Kagyu, and Tshalpa Kagyu. Another of Milarepa’s students, the yogi Rechungpa, brought several important transmissions into the Karma Kagyu lineage. Along with Gampopa, Rechungpa was a teacher of the 1st Karmapa Dusum Khyenpa [1110-1193]. Upon meeting Dusum Khyenpa, Gampopa told his students, "He is pretending to be a disciple of mine in order to hold my lineage for future sentient beings, but in actuality, he has already accomplished the goal of the path. "