The term “Extremadura” is credited with two sources. The first is an apparent error in geography or translation: “The extreme reaches of the Duero River in Iberia.” More recent research suggests that the name originated from “estremad” meaning “separated” and “ura” which implies the practice of herding animals in a year-round pasturing location; a Roman practice.
Indigenous Iberians had long been venturing inland as the coastal areas became more densely populated. Typical paths of settlement would progress up river valleys such as the Guadiana River basin.
At that time (400 B.C.) Carthaginians were in control of southern Iberia and many, like Hannibal, had taken Iberian wives. Hannibal controlled southern Iberia and northward as far as present day Merida.