The Inca, led by Manco Capac(leader of the ayllu, a nomadic tribe), migrate to the Cuzco Valley and establish their capital at Cuzco. Upon arriving to the Cusco valley, they defeated three small tribes that lived there; the Sahuares, Huallas and Alcahuisas, and then settled in a swampy area between two small streams, that today corresponds with the main plaza of the city of Cusco. Manco Capac oversees the construction and development of the Kingdom of Cusco, initially a small city-state. Archaeologist John Rowe calculates 1200 AD as an approximate date for the founding of the Inca dynasty — long before the foundation of the empire.