The Roman concept of the citizen evolved during the Roman Republic and changed significantly during the later Roman Empire. After the Romans freed themselves from the Etruscans, they established a republic, and all males over 15 who were descended from the original tribes of Rome became citizens. Citizens of Rome distinguished themselves from slaves and other noncitizens by wearing a toga; most wore a white toga. During the Empire, each emperor wore a purple toga to distinguish himself as the princeps, or "first citizen."
Citizenship varied greatly. The full citizen could vote, marry freeborn persons, and practice commerce. Some citizens were not allowed to vote or hold public office, but maintained the other rights. A third type of citizen could vote and practive commerce, but could not hold office or marry freeborn women.
In the late Republic, male slaves who were granted their freedom could become full citizens. Around 90 B.C.E., non-Roman allies of the Republic gained the rights of citizenship, and by 212 C.E, under the Edict of Caracalla, all free people of the Roman Empire could become citizens.
