Saint Augustine 
The Confessions of St. Augustine [EPUB ebook] 

The confessions of St. Augustine feature an autobiographical work depicting Augustine’s sinful youth and his conversion to Christianity. It is widely seen as the first Western autobiography ever written, and was an influential model for Christian writers throughout the following thousand years of the Middle Ages. It is not a complete autobiography, as it was written in his early 40s, it does, nonetheless, provide an unbroken record of his development of thought and is the most complete record of any single person from the 4th and 5th centuries.