Rome was founded on seven hills along the Tiber River in Italy. By the 2nd century BC, Rome had expanded throughout the Italian peninsula and beyond to control Spain, North Africa, Greece, Gaul and parts of Asia. At its height in the 1st century BC under Augustus, the Roman Empire stretched from Britain to Egypt. However, military overspending and economic difficulties later contributed to the decline and fall of the Western Roman Empire in the 5th century AD.