While Charles V assumed the functions of Holy Roman Emperor in Germany, the conquistador Hernán Cortés informed him of the ongoing Spanish conquest of the Aztec Empire, including the discovery of Tenochtitlan and the death of its ruler Montezuma during a local revolt, in a relation letter that widely circulated and became the basis of European knowledge on the Aztec Empire. Combined with the contemporary circumnavigation of the globe by Magellan and with the idea (proposed for the first time, although not realized) of constructing an American Isthmus canal in Panama, this success convinced the Emperor of his divine mission to unify the world as the leader of Christendom. In his letter, Cortés claimed to have added to the empire as many provinces as Charles's Burgundian, Spanish, and Austrian ancestors, and described Mexico to be "no less worthy than Germany to warrant your assuming anew the title of Emperor, of which, by the grace of God, Your Sacred Majesty already possesses the title."[Cortés, Hernán. Letters – available as Letters from Mexico translated by Anthony Pagden. Yale University Press, 1986. . Available online in Spanish from an 1866 edition.
