The figure of Girolamo Savonarola looms large over Italian secular and ecclesiastical history, but remains obscure to the English-speaking world. Now, as part of a larger project dedicated to the translation and study of the life and works of Savonarola, this highly accessible biography of the Friar of San Marco has been republished in the hopes of introducing faithful Catholics to a man that Pius XII called "an apostle who has a lively sense of things divine and eternal, who takes a stand against rampant paganism, who remains faithful to the evangelical and Pauline ideal of integral Christianity put into action in public life."

In the first part of the book, O'Neil presents the public career of Savonarola in the style of a chronicle. In the second part, he traces a portrait of the friar himself, drawing on his own writings and sermons, which are further explored in an appendix.