Final answer:
The emperor of the Aztec Empire when Hernán Cortés landed in Mexico was Moctezuma II. Cortés initially received a warm welcome but later took Moctezuma hostage. The siege and fall of Tenochtitlán marked the end of Moctezuma's rule and the Aztec Empire.
Step-by-step explanation:
The Emperor of the Aztec Empire
When the Spanish conquistador Hernán Cortés landed on the coast of Mexico in 1519, the emperor of Mexico or the Aztec Empire was Moctezuma II. Cortés was met with significant intrigue and complex political situations upon his arrival. The Aztec capital, Tenochtitlán, was a city of immense wealth and complexity, ruled by Moctezuma II, who was later held hostage and died during the subsequent events that led to the fall of the Aztec Empire.
Cortés's encounter with the Aztecs is documented in letters to King Charles I of Spain, Bernal Díaz del Castillo's 'True History of the Conquest of Mexico', and indigenous accounts such as 'Broken Spears: An Aztec Account of the Conquest of Mexico'.
As Cortés entered Tenochtitlán, he was initially well-received by Emperor Moctezuma II. However, following an attack on Spanish soldiers, Cortés took the emperor hostage. The subsequent siege of Tenochtitlán led to the downfall of Moctezuma and the eventual surrender of the Aztec capital in 1521. The story of Cortés and Moctezuma represents the dramatic and violent clash between the Old World and the New, reshaping the history of the Americas forever.