• They arrived in a Mediterranean land with farming resources that were basically similar to those of Greece or Palestine.
• The Indo-European settlers formed various tribal groups, among them the Latin people of central Italy. Some of the Latins settled near the mouth of the Tiber River.
• The Etruscans were non-Indo-European immigrants who arrived in Italy from somewhere to the east about the ninth century B.C. 
• The Greek city-states had begun to plant colonies in southern Italy as early as the eighth century B.C. 
• The Latins first learned the alphabet and gained knowledge of the life of Greek city-states.
• The King was advised by a council of elders called the Senate (from the Latin senex, meaning "old man".
• Usually, he chose from among the patricians or "men with fathers".
• Around 500 B.C., Rome overthrew its Etruscan rulers, and the monarchy was also abolished. 
• Plebeians (from the Latin plebs, meaning "the common people").
• In the earliest times of the Republic, the "people's business" was in practice run by the Senate, an assembly of about three hundred heads of patrician families. Two among the senators functioned as consuls ("colleagues"), wielding for a year at a time the military and government power that had formerly belonged to the kings. 
• This slowed down government decisions and actions, but in time of emergency the councils, on the advice of the Senate, could appoint a dictator, with full power to give orders and make laws for a maximum period of sixth months.
• Among the chief complaints of the plebeians was that they lacked legal protection.
• About 450 B.C., in response to the plebeians' demand, the laws of Rome were set down in writing. The new code was said to have been engraved on twelve slabs of wood or bronze and mounted in the chief public square, the Forum, for all to see. 
• The other, in which farmers from outside the city had a larger say, began electing their own magistrates, called tribunes. The Tribunes eventually gained the power to initiate laws in their assembly and veto laws passed by the Senate.
• The separation of powers in the U.S. Constitution derives ultimately from the checks and balances between different branches of government in the Roman city-state.