The migrations of Indo-European peoples into Italy probably began about 2000 B.C. and continued until 1000 B.C. From about the 9th century B.C. until it was overthrown by the Romans in the 3rd century B.C. , the Etruscan civilization was dominant. By 264 B.C. , all Italy south of Cisalpine Gaul was under the leadership of Rome. For the next seven centuries, until the barbarian invasions destroyed the western Roman Empire in the 4th and 5th centuries A.D. , the history of Italy is largely the history of Rome. From 800 on, the Holy Roman Emperors, Roman Catholic popes, Normans, and Saracens all vied for control over various segments of the Italian peninsula. Numerous city-states, such as Venice and Genoa, whose political and commercial rivalries were intense, and many small principalities flourished in the late Middle Ages. Although Italy remained politically fragmented for centuries, it became the cultural center of the Western world from the 13th to the 16th century.