Well, if you're asking an area where they lived before Italy, then a DNA study done in 2013 points towards them being from a Neolithic population in Central Europe. And before that, The consensus is that Homo sapiens migrated out of Africa anytime between 150,000 and 200,000 years ago. The aforementioned study also shows them genetically close to other Tuscan populations, so intermarriage was certainly not taboo.

If you're wondering about their more "modern" history, the Etruscan culture became dominant circa 800 BCE, taking the place of the Villanovan culture that was common to that point. Strabo, Herodotus, and Dionysius of Halicarnassus all say the Pelasgians migrated to Italy and brought the culture with them, led by Tyrrhenos/Tyrsenos, the son of the Lydian king Atys. Strabo mentions that the Pelasgians were from Lemnos and Imbros, cities in the Aegean Sea. This link was strengthened by the Lemnos Stele, which currently resides in a museum in Athens. It has language in it that resembles the still-mostly-untranslated Etruscan language. The Etruscan culture flourished from then until sometime around 500BCE, when The City of Roma began her conquests, and along with Roman rule came Latin culture. The Etruscans as a political entity were organized into three "major" confederations of cities, each of which gradually declined after the Romans started conquering, and by 100BCE the last of the independent Etruscan cities were formally annexed to the Roman Republic.

Hope this helps!

Sources: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0055519

Any of the ancient historians I mentioned above, although I know it's tedious to look through their extensive works.

Robert D. Morrit, Stones That Speak, pg 210