When Montezuma Met Cortés: The True Story of the Meeting That Changed History by Matthew Restall Ecco, 526 pp., $35.00

On the road to Toboso, where he is hoping to meet Dulcinea, Don Quixote talks to Sancho Panza about the nature of fame. He mentions four characters from classical literature who achieved it by acts of unlikely valor, Julius Caesar among them. Then he adds a more modern figure: “the gallant Cortés.” Appearing in Don Quixote alongside Julius Caesar is no mean achievement for a member of the minor aristocracy who enriched himself as a bureaucrat on the furthest shores of the Spanish empire.

The reference in Don Quixote de La Mancha is not the only one Cervantes makes to Hernán Cortés. In “The Novel of the Glass Lawyer,” one of the stories in the Exemplary Novels, he mentions Cortés in passing when writing about Venice:

But thanks be to heaven and the great Hernando de Cortés, who conquered great Mexico City so that great Venice would in some way have some competition. These two famous cities resemble each other in their streets, which are all of water: the one in Europe, the admiration of the old world; the one in America, the fright of the new.

That to Cervantes, Cortés should be like Julius Caesar, and that Tenochtitlan—the original name for Mexico City—was a fright (espanto), gives a clear sense of seventeenth-century imperial Spain’s perception of the Conquest of Mexico. Cortés was a figure with the stature of a classical hero, and the city of Tenochtitlan an abomination that was subjugated and occupied by Spain, with Providence guiding Cortés’s arm.

This perception has changed. Any military occupation that directly or indirectly caused the deaths, in less than a century, of 90 percent of the population is hardly one to celebrate. It is true that Aztec civilization continues to be seen as a particularly bloodthirsty one, but the general assessment of it has also become more sophisticated. If Cervantes—a knowledgeable dissident in his time—lived today, he would recognize Cortés as a genocidal killer and would not define Tenochtitlan as a “fright” but as a triumph of environmentally sound engineering whose inhabitants suffered from a worrying tendency to make violent death into a performance.

In When Montezuma Met Cortés, the American historian Matthew Restall examines documents concerning the military conflict that set the Aztecs in opposition to the Spanish empire in 1520. His aim is to reassess the process of simplification by which Cortés, in his letters to King Carlos I (also Charles V of the Holy Roman Empire), justified the permanent occupation of Mexico and gave it a moral basis. Cortés’s vaguenesses and generalizations were extraordinarily effective—you might accuse him of many things, but not of being unable…