As a result of social class struggle in the Roman Republic, a new patrician-plebeian aristocracy evolved – nobility. The Roman Republic has always remained an aristocratic republic, where the governing body was the Senate. The Senate actually ruled the state, subordinating the will of magistrates. In Rome, at the same time were three kinds of popular assemblies: curiate, centuriate and tribal. The highest magistrate of the republic was consulate. Praetorship became predominantly judicial magistracy, and the most honorable is censorship. The public tribunat maintained its position exclusively as plebeian magistracy. Skillful execution of aedilis determined a successful political career.
The Constitution of the Roman Republic is a set of guidelines transmitted mostly through precedent. The Constitution was largely unwritten, uncodified, and constantly evolving. Instead of creating the political regime, which primarily would be democratic (as in ancient Athens), aristocratic (as it was in ancient Sparta), or monarchical (as it was in early Rome), the Roman constitution was a mixture of these three elements, creating thus three separate branches of government. The democratic element expressed by the national assembly, the aristocratic element has taken the form of the Senate, and the monarchical element took the form of many short-term executive magistrates.
The main source of sovereignty in this ancient republic, as well as in modern republics, was Populus Quiritium Romanus, that is, all the citizens, Roman people. Roman people held assemblies to adopt laws and elect the executive magistrates (comitia). The election to the magistracy entailed an automatic membership in the Senate (as a rule for life, except in cases of expulsion). Senate ruled the current affairs in Rome, while senators presided in the courts. Magistrates kept an eye on the compliance to the law, and had more executive power than the Senate and the national Assembly. A complex set of checks and balances was designed for a balance between the three branches of government in order to minimize the risk of arbitrariness and corruption, and to maximize the probability of a good government. However, the separation of powers between the three branches of power was not absolute. In addition, there has been frequent use of several constitutional institutions, which were contrary to the constitution of the Roman Republic. Constitutional crisis began in 133 B.C. as a result of the struggle between the aristocracy and the people. This crisis eventually led to the collapse of the Roman Republic and the Roman Empire.
As a result of social class struggle in the Roman Republic, a new patrician-plebeian aristocracy evolved – nobility. The Roman Republic has always remained an aristocratic republic, where the governing body was the Senate. The Senate actually ruled the state, subordinating the will of magistrates.