Montezuma II was the ninth ruler of the Aztec Empire, reigning from 1502 to 1520. He is known for expanding the empire and increasing its wealth through tribute from conquered territories. His leadership coincided with the arrival of Spanish explorers, which would ultimately lead to significant changes in the region. During his reign, Montezuma II oversaw the construction of impressive architectural projects, including the expansion of the Great Temple in Tenochtitlan. He was also known for his complex relationship with the Spanish conquistador Hernán Cortés, which played a crucial role in the fall of the Aztec Empire.