Bernal Díaz del Castillo (1492-1584) was a Spanish conquistador and historian who played a significant role in the Spanish conquest of the Aztec Empire in the early 16th century. Born in Medina del Campo, Spain, he traveled to the New World in search of adventure and fortune. Díaz del Castillo is best known for his firsthand account of the conquest, "The Conquest of New Spain," which provides a detailed and vivid narrative of the events from the perspective of a soldier involved in the expedition led by Hernán Cortés. His work stands out for its detailed descriptions of battles, the customs and cultures of the indigenous peoples, and the political dynamics within the Spanish expedition. Despite controversies over its accuracy and biases, his account remains one of the most important and influential primary sources for understanding the Spanish conquest of Mexico and the fall of the Aztec Empire.