Roman law was rooted in Etruscan religion, which was steeped in ritual. (The Etruscan civilization was the culture of western central Italy from ~800 BCE until Roman times.) Noble Roman families claimed Etruscan descent, and thereby its cultural precepts endured.
753 BCE is the legendary founding date of Rome by Romulus, who reigned until 715 BCE. The next 4 kings were elected by the Romans. The popular 6th king, Servius Tullius, inherited the throne.
The 7th and last king of Rome, Tarquinius Superbus, known as Tarquin the Proud, was an usurper who murdered Servius Tullius to gain the throne. He reigned from 535 BCE until overthrown by popular revolt in 509 BCE. This led to the founding of the Roman Republic (509–27 BCE), which lasted until Augustus was made “1st citizen” (princeps), and the Roman Empire (27 BCE–395) ensued.
There was a long struggle between patricians and plebeians in the early years of the republic. One of the concessions made by patricians in mid-5th century BCE was legislation termed the 12 Tables, which granted basic procedural rights to all Roman citizens regardless of rank.
The 12 Tables were by no means a reform or liberalization of custom. Rather, they recognized the prerogatives of the patrician class, the validity of enslavement for unpaid debt, and the interference of religious custom in civil disputes. The 12 Tables were nonetheless advanced for their time, particularly with respect to property rights and commerce: providing for testamentary rights (inheritance) and contract enforcement. This reflected the extent and vigor of trade and commercial customs in that era.
Based on custom and legislation, Roman civil law (jus civile) evolved during the early republic. Roman law, like other ancient systems, adopted the principle of personality, whereupon legal rights extended only to citizens. Foreigners only had rights where their homeland had a mutual protection treaty with Rome. From early times such treaties existed in the interest of commerce.
By the mid-3rd century BCE, a massive body of law had been built – via magistrate rulings – that applied to both citizens and foreigners (jus gentium). This case law alternately derived from existing mercantile law used by Mediterranean traders, Roman law, and what a jurist might have considered fair and just.
Citizenship was extended throughout the empire ~200 BCE, largely erasing the distinction between jus civile and jus gentium. Even before this, when a Roman lawyer argued that a contract was juris gentium, he meant that it applied regardless of the parties’ citizenship.
This envelopment became the practical meaning of jus gentium. Because of its universality of application, jus gentium became linked with the theory of natural law, which the Romans adopted from the Greeks.
The Romans relied upon written and unwritten law. Custom was the basis for unwritten law.
The constitution of the Roman Republic was largely unwritten: the product of custom and constantly evolving.
Concepts that originated in the Roman constitution live on to this day. The notions of scheduled elections, block voting (such as used in the US electoral college), separation of powers, checks and balances, powers of the purse, term limits, impeachment, vetoes, and quorum requirements all originated in early Roman times.
During the 1st century BCE, the power and legitimacy of the Roman constitution eroded. The constitution died with the republic, though Augustus gave the appearance that a constitution still governed the empire.
The duration from the rule of Augustus, which began in 27 BCE, to the death of Roman jurist Ulpian in 223, is considered the classical period of Roman law. There was an expansion of legal specialists, empowerment of jurists, and a flowering of literature on jurisprudence.
Depending upon the era, written law might come from any of various sources: general assemblies, plebeian resolutions (whence the term plebiscite), magistrate edicts, the senate, or legislative expression by the emperor. Regardless of the times, magistrates had considerable discretion in their exercise of the law.
The Roman legal system affected the development of law in Western civilization, and later derivative regimes throughout the world.
In early civilizations, the upper classes and the major institutions they controlled had far more wealth and privileges to protect than did commoners, and they relied on the law to do this. In some early civilizations, growing concern to protect property resulted in increasingly severe penalties for theft. An important function of the legal system was to reinforce the power and privileges of the state and upper classes. Between men of unequal status, the more powerful was invariably deemed to be in the right, and therefore litigation could occur only between equals. ~ Bruce Trigger