Columbus’s famed voyages are so over-researched that it easy to assume that nothing new could ever be said about them. And yet Nicolás Wey Gómez has managed the seemingly impossible task of not just adding a few new details but indeed opening vast new vistas on this subject. He accomplishes this feat not by unearthing previously unknown letters or a long-lost manuscript but by offering us a new lens through which to contemplate the Columbian project. As the subtitle indicates, Wey Gómez makes the case that as much as Columbus intended to travel west to reach the East it was also part of his plan to sail south. And he contends that this overlooked aspect of Columbus’s enterprise, far from constituting a minor variation on the standard narrative, in fact shows the Columbian enterprise in a wholly new light.At 592 pages this is a jungle of a book with exuberant sections, lengthy excursus, some redundancy, and a breathtaking scope. But regardless of the difficulty of the terrain, Wey Gómez always finds a way to pursue his argument in ancient, medieval, or early modern texts and around the globe. If nothing else, The Tropics of Empire is inspiring for the sheer simplicity of its central idea but boundless ambition with which it is carried out.Does it succeed in recasting the Columbian narrative? In the eyes of this reviewer the answer is resoundingly yes. The Tropics of Empire opens exciting avenues of understanding and research in at least three broad areas. First, by emphasizing Columbus’s decision to go south, we better appreciate the monumental shift in geographic thinking implied in Columbus’s conceptions. Since antiquity, Western thinkers like Parmenides, Virgil, Pliny, and many other authorities had imagined the earth as a series of climate belts, with Mediterranean Europeans inhabiting a temperate region, followed by a warmer band to the south called the “torrid zone,” widely depicted as barren and uninhabited. Columbus’s decision to sail there reveals the dawn of a completely new geographic understanding that turned venerable notions of the past on their head by casting the south as especially lush, rich, and well populated. As is well known, Columbus defied conventional wisdom by sailing west to reach the East. But his bet was double or nothing as he also took exception to a multisecular geographic tradition regarding latitude.Second, The Tropics of Empire is immensely valuable for highlighting the close links between the Portuguese explorations and the Columbian project. The Portuguese were the first Europeans who dared to venture into the torrid zone as they explored the west coast of Africa south of Cape Bojador. Columbus, a proficient mariner and mapmaker, not only kept abreast of these discoveries but in fact took part in them by visiting the fortress of São Jorge da Mina in the equatorial coast of Guinea and by spending years in Portugal in the late 1470s and early 1480s. While the standard historical literature treats Spain and Portugal as two separate imperial systems, in fact multiple contacts were the norm, particularly within the notoriously cosmopolitan and fluid world of cartographers and pilots. The lesson of Portuguese precedents needs to be extended to other aspects of Spain’s activities in the Americas.A third crucial contribution of The Tropics of Empire is to flesh out Columbus’s colonial project especially with regard to the peoples that he found in the Americas. Columbus, like other Europeans of his time, was heir to an enduring nexus of ideas linking particular locales in the world with the physical and mental characteristics of their inhabitants. But it is only by considering his deliberate drift southward that we begin to understand just why the great discoverer was an early and persistent proponent of the enslavement of Indians, as he expected to find in those tropical latitudes “child-like” or “monstrous men” well suited for such purposes.These areas hardly encompass the range of subjects treated in this book. But after reading this book one cannot escape the conclusion that there is much to be gained by considering the Columbian enterprise not only along an East-West axis but also along a North-South one. MIT Press is to be commended for a splendid production with high-quality paper, elegant chapter breaks, essential maps, and, that rarest of commodities in history books, color illustrations. All told, this is an exceptional book.