A remarkable bit of detective work this; while Caravaggio's life is much storied -- chiefly about the brawls, his murder of a man in Rome, and his own mysterious death -- the physical evidence documenting that life is scanty at best, and much is hearsay. Robb uses the documented paintings to establish a biographical timeline of sorts, and gathers together much supporting evidence to build a compelling, sympathetic life of the proto-baroque master. His story is solidly grounded in the context of the artistic and political milieu of Italy at the beginning of the 17th c., at the height of the Counter-Reformation. Altogether he creates a convincing narrative of a passionate, but occasionally rash -- and violent -- genius, haplessly caught between powerful competing interests and in a web of papal/political intrigue. Robb's theory of Caravaggio's mysterious, untimely death is probably closer to the truth than any offered before. I have a couple of caveats, however: first, I would recommend anyone picking this up get their hands on a good monograph of Caravaggio's paintings (happily I had John T.Spike's), as the book includes color plates of only a few key paintings, as well as some details focusing on the models who recur in his work. As the text discusses each of his documented works in some detail, and often uses them to make biographical inferences, not being able to examine the images Robb is discussing -- in some detail -- is frustrating. Second, the author is Australian, and while his jocular, colloquial writing style is very engaging, he occasionally employs bits of Aussie slang which were wholly unfamiliar, and a bit baffling at first, to this American reader. However, usually one can tease out his meaning through the overall context of the term within the narrative.
I would certainly recommend "M: The Man Who Became Caravaggio" to anyone who, like myself, is a lover of his painting, for both an insightful critique of his works and perhaps the best biography we'll ever have of the fascinating, turbulent man who created them.