The trouble with history is, we weren't there when it took place and it can be changed to fit someone’s belief and/or traditions, or it can be taught in the public schools to favor a political agenda, and withhold many facts.
"The term citizen was used in Rome to indicate the possession of private civil rights, including those accruing under the Roman family and inheritance law and the Roman contract and property law. All other subjects were peregrines. But in the beginning of the 3rd century, the distinction was abolished and all subjects were citizens; 1 sel. Essays in Anglo-Amer. L. H. 578." ~ Bouvier's Law Dictionary, 1914.