At the time of the great northern glaciers, Native Americans followed the game they hunted to Virginia. Ten thousand years later, as the cold of the Ice Age gave way to a warmer, drier climate, they relied also on foraging and farming. After about 900 CE they settled into villages that united into chiefdoms. In 1607, in pursuit of opportunity in a new world, English settlers intruded into an eastern Virginia chiefdom of thirty-two tribes (15,000 to 20,000 people). Its leader then was Wahunsenacawh, whom the new settlers called by his title, Powhatan.