St Augustine of Hippo is credited with Having (arguably) written the 1st Biography. St. Augustine questioned the Church on every Facet from the validity of the scriptures especially Genesis, to corruption, to the role of the men of God and how they relate to the Church to they very existence of God.
At the time Augustine lived The Pope was the Head politician in charge (so to speak) During the time after the fall of Rome people simply Did not question their Lords.
Augustine Having Studied Plato and Been formally educated, used his education to start a monastery, help the poor and educate priests.
At the time The Roman Catholic Church had fallen into a sort of Apathy, wealth, Monarchs buying titles etc. Augustine Helped influence the Church back onto the path of righteousness. Christ originally set it on.