Final answer:
The first phase of Etruscan civilization is marked by the Villanovan Culture, within the Iron Age, starting around 900 BCE.
Step-by-step explanation:
The first phase of Etruscan civilization, which was still not considered a fully developed civilization, is marked by the Villanovan Culture. This early culture was the foundation before the Etruscans transitioned into a more complex society.
The Villanovan Culture is considered part of the Iron Age, starting around 900 BCE and characterized by its distinctively geometric iron artifacts and cremation urns shaped like huts. This culture reflects the earliest Etruscan life, which was influenced by various contacts with other cultures around the Mediterranean, particularly through trade.