There are no historical records relating to the birth and life of Mahavatar Babaji. Paramahansa Yogananda has written in Autobiography of a Yogi that the deathless avatar has resided for untold years in the remote Himalayan regions of India, revealing himself only rarely to a blessed few.
It is Mahavatar Babaji who revived in this age the lost scientific meditation technique of Kriya Yoga. In bestowing Kriya initiation on his disciple Lahiri Mahasaya, Babaji said, "The Kriya Yoga that I am giving to the world through you in this nineteenth century is a revival of the same science that Krishna gave millenniums ago to Arjuna; and that was later known to Patanjali and Christ, and to St. John, St. Paul, and other disciples."
Shortly before Paramahansa Yogananda left for America in 1920, Mahavatar Babaji came to Yoganandaji's home in Calcutta, where the young monk sat deeply praying for divine assurance regarding the mission he was about to undertake. Babaji said to him: "Follow the behest of your guru and go to America. Fear not; you shall be protected. You are the one I have chosen to spread the message of Kriya Yoga in the West."
Read more about Mahavatar Babaji: Babaji, Yogi-Christ of Modern India
A Blessing from Mahavatar Babaji