History of the Constitution of the Roman Republic
The history of the Constitution of the Roman Republic is a study of the ancient Roman Republic that traces the progression of Roman political development from the founding of the Roman Republic in 509 BC until the founding of the Roman Empire in 27 BC. The constitutional history of the Roman Republic can be divided into five phases. The first phase began with the revolution which overthrew the Roman Kingdom in 509 BC, and the final phase ended with the revolution which overthrew the Roman Republic, and thus created the Roman Empire, in 27 BC. Throughout the history of the republic, the constitutional evolution was driven by the struggle between the aristocracy and the ordinary citizens.
Servius Tullius
Before its establishment as a Republic, Rome was ruled by kings (Latin "reges", singular "rex"). In Roman tradition, Rome's founder Romulus was the first. Servius Tullius was the sixth, and his successor Tarquinius Superbus (Tarquin the Proud) was the last. The nature of Roman kingship is unclear; most Roman kings were elected by the senate, as to a lifetime magistracy, but some claimed succession through dynastic or divine right. Some were native Romans, others were foreign. Later Romans had a complex ideological relationship with this distant past. In Republican mores and institutions kingship was abhorrent; and remained so, in name at least, during the Empire. On the one hand, Romulus was held to have brought Rome into being more-or-less at a stroke, so complete and purely Roman in its essentials that any acceptable change or reform thereafter must be clothed as restoration. On the other, Romans of the Republic and Empire saw each king as contributing in some distinctive and novel way to the city's fabric and territories, or its social, military, religious, legal or political institutions. Servius Tullius has been described as Rome's "second founder", "the most complex and enigmatic" of all its kings, and a kind of "proto-Republican magistrate".