When Europeans arrived on the western shores of South America early in the 16th century, they encountered the empire of the Incas at its greatest extent. At that time, it was the largest empire in the world, stretching nearly 2,500 miles along the Pacific shore and over the ridge of the Andes, similar to the extent of the Roman Empire at its peak. Its emperor, the Inca, ruled over millions of people of diverse ethnic backgrounds. The empire was tied together by a 10,000 mile network of stone-paved roadways, some as wide as 24 feet, paralleling the Pacific coast and criss-crossing through the rugged spine of the Andes. A series of runners, called chasquis, carried information between points at remarkable speed, utilizing quipus, a system of knotted strings, to help them remember the message accurately, as the Incas had no written language.
The Incas and their predecessors had built extensive terraces over thousands of miles of steep mountainside. These and their hardy, varied crops allowed them to produce enough surplus food to build a vast empire. In a land in which money did not exist and gold (called "tears of the sun") was valued only for its beauty, workers and soldiers were paid in food and textiles.
The ancestors of the Incas were three tribes that migrated into the valley where two rivers joined in southern Peru, in approximately the thirteenth century, under the leadership of the first Inca, Manco Capac. They joined forces with a fourth tribe, already living in the area, expelled other residents and established the city of Cuzco. As Lords of Cuzco, they consolidated their hold over the region for nearly two hundred years. It was the fifth of these lords, Inca Roca, who initially took the title "Inca", which eventually came to mean "emperor". Although this is the commonly accepted beginning of the Inca Empire another exists. The legend says that the Andean creator-god Viracocha gave Manco Capac and his sister-wife, Mama Ocllo, a golden rod and told them to search for a homeland where they could settle and establish a city.