In 1609, Inca Garcilaso de la Vega published his famous Royal Commentaries in Lisbon, a monumental work that became the first great history of Peru told from within. Born in Cusco in 1539, the son of a Spanish conquistador and an Inca princess, Garcilaso was a privileged witness to a disappearing world. His mestizo voice, both American and European, managed to build a unique bridge between two opposing civilizations. GARCILASO'S IDEALIZED VISION OF INCA CIVILIZATION, HIS CONSTANT COMPARISON WITH THE EUROPEAN LEGACY, AND HIS DESIRE TO INTEGRATE BOTH WORLDS INTO A COMMON IDENTITY. These pages recount the customs, myths, beliefs, laws, and exploits of the Thirteen Incas who built the vast Tahuantinsuyo empire, stretching from Quito to Chile and Argentina. Unlike European chroniclers, who wrote from hearsay, Garcilaso drew on the oral memory of his childhood, the testimony of his relatives, and his knowledge of the Quechua language, which made him the most reliable and sensitive interpreter of the Andean world. Eduardo Alonso offers an adaptation of the Royal Commentaries into modern Spanish, respecting their literary essence and classical flavor, but making them easier to read for a contemporary audience. It is not a simple summary, but a careful reduction that preserves the essential. Inca Garcilaso was more than a chronicler; he was a universal man who recognized in the amautas—the Andean sages—a greatness comparable to that of the classical philosophers, and in the institutions of the Tahuantinsuyo, similarities with Christianity and Western culture. With his pen, he enriched Spanish with Quechua words and vivid descriptions, giving rise to a mestizo literary style that anticipated Creole literature and 19th-century Peruvian nationalism. This adaptation turns a seminal work into an accessible and captivating text, essential for understanding the conquest of Peru, the foundations of Hispanic America, and the cultural legacy of one of its most illustrious writers.