Some books interest only specialists, some cater only to a general audience; rare is the book that can satisfy the stringent demands of specialists and at the same time prove enlightening and engrossing to a wider reading public. John W. O’Malley’s Trent: What Happened at the Council is such a book. With a clarity and grace that make it a joy to read and a scholarly precision and richness that make it useful to experts, O’Malley’s Trent provides the first one volume overview in English and, in fact, the best in any language, of one of the most complicated and crucial events in Catholic religious history, laying out not only what happened at the Council, as the book’s title promises, which would be challenging enough because of the Council’s eighteen year history, but also the long, intricate pre-history of the Council and, in a masterful Epilogue, the Council’s impact, successes, and failures. This is a book that will endure, be cited by historians, quoted by many because of its apt phrasing, and enjoyed by students, scholars, and educated readers for a long time to come.