The book "Autobiography of St. Ignatius" is an important testimony of the life and spiritual development of St. Ignatius of Loyola, the founder of the Jesuit Order. In this autobiography, the saint tells about his spiritual journey, his transformation from a warrior to a follower of Christ, as well as about the discovery of the method of spiritual exercises, which later became known as the "Spiritual Exercises of St. Ignatius." The book is a valuable source for understanding the spirituality and spiritual experience of Ignatius of Loyola, as well as the history of the development of the Jesuit order.