When did people begin living on the Italian peninsula?
According to http://quatr.us/romans/history/stoneage.htm, during the Upper Paleolithic period, the peninsula of Italy was populated by indigenous people. The people were cave dwellers who left behind paintings from around 10,000 B.C. The earliest people were few in number and made simple weapons to use, such as flint axes and other types tools made from stone. They are believed to have arrived there from West Asia.
The Etruscan civilization began in the center and northern areas of the peninsula. DNA studies have traced the lineage and determined that the Etruscan people were indigenous to the area, which would mean that they were decedents of the original cave dwellers.
The Etruscan civilization engaged in trade with other people and made weapons from iron. By the 6th century the influence of the Etruscans had traveled to other regions in Italy and is believed to have provided an influence on Rome (http://www.timemaps.com/civilizationetruscans).
By 5,000 B.C. new technology was introduced by the arrival of people from Greece and other areas who had traveled to Italy by boat, according to http://www.historyworld.net/. The peninsula was not known as Italy and would not be called Italy until sometime between 1 B.C. and the 5th Century. The population came under the control of Rome in the 1st century before Christ.