First an oligarchy and then a developing limited democracy.
Monarchy.
Etruscans, Latins and the Sabines
The Etruscans. They influenced Rome's daily life, government, and military, since they were the Romans.
Rome's government began with the overthrow of the Etruscans in 509 B.C.E. The Roman's then established a republic. It is a government in which citizens elect representatives to rule on their behalf.
No.
The Etruscans
No.
They were bithces
The Etruscans were a civilization that lived on the northern part of the Italian Peninsula. They were the people who founded Rome. Later, the Romans revolted from them.
Although the theory that the Etruscans conquered Rome is very fashionable, it is just that, a theory. It is based on unproven assumptions and it evidence base is flimsy, to say the least. It is most likely that the Etruscans did not conquer Rome. There is no record of it. More recent archaeological finds seem to suggest a different picture.
They didn't "win" Rome. They created it. Before the Etruscans there may have been a small village of people, but it wasn't a city state nor what we think of as "Rome."
Etruscan were the barbarians of Rome.