Hernán Cortés was a Spanish explorer and conquistador who led an expedition to Mexico in the early 16th century. He is most known for his interactions with the Aztecs, an advanced Mesoamerican civilization. Upon arriving in Mexico, Cortés and his troops were initially welcomed by the Aztec ruler, Montezuma II. However, relations quickly soured due to a combination of cultural misunderstandings, brutal Spanish treatment of the Aztecs, and Montezuma's perceived weakness in dealing with the invader