In the 16th century, Spanish conquistadors arrived in the Andes and encountered the vast Inca Empire-a civilization of extraordinary engineering, communication networks, and cities like Machu Picchu. Yet within a few decades, this powerful realm collapsed under foreign conquest. What forces truly brought down the Inca-military strategy, disease, internal conflict, or fate?In the 16th century, Spanish conquistadors arrived in the Andes and encountered the vast Inca Empire-a civilization of extraordinary engineering, communication networks, and cities like Machu Picchu. Yet within a few decades, this powerful realm collapsed under foreign conquest. What forces truly brought down the Inca-military strategy, disease, internal conflict, or fate?