The main source of what we know about Guido Reni is The Life of Guido Reni by Malvasia. It lets us see a major artist of the Italian Baroque through the eyes of his own age. The text contains considerable detail on what Guido painted, as well as his commissions and patrons. As Reni's close friend, Malvasia took much of his material from first-hand knowledge; documentary evidence from the artist's recently discovered account book attests to the reliability...