The Inca Empire was a vast civilization that existed in South America from the early 15th century until the Spanish conquest in the 16th century. It was centered in present-day Peru and extended across parts of Ecuador, Bolivia, Chile, and Argentina. The Incas are known for their advanced agricultural techniques, impressive stone architecture, and extensive road systems that connected their territories. The empire was ruled by a series of emperors, the most famous being Pachacuti, who expanded the empire significantly. The Incas spoke Quechua and practiced a form of state-controlled economy. Their capital was Cusco, which served as a political and cultural hub.