How a Roman emperor shaped our civil rights 2,000 years ago

Today, anyone who holds a passport, pays taxes or can enforce their rights in court is part of a much longer story than many realise. One key building block of modern citizens’ rights can be traced back to a year that feels remote: AD 212. That was when the Roman emperor Caracalla introduced a reform that reshaped his empire - and still echoes through the way modern states are organised.

A quiet thunderclap in AD 212: almost all free people become Romans

In AD 212, Caracalla issued an edict later known as the Constitutio Antoniniana. Its effect was startling: nearly all free men across the Roman Empire were granted Roman citizenship. Until then, only a small minority - around 10 to 15 percent - had held that status.

Before the edict, society was split by a hard legal boundary. On one side stood full Roman citizens with extensive rights; on the other was the overwhelming majority of so‑called foreigners, the peregrini. With a single political act, Caracalla largely blurred that divide.

With one edict, a patchwork of subjects became a vast community of citizens - at least on paper.

Roman citizenship was not merely an honorary label. It came with concrete advantages:

• legally recognised rights of marriage
• secure inheritance and property rights
• clearly regulated naming conventions using three Latin names
• access to Roman courts and legal remedies

For many people living in the provinces, this was a dramatic shift. They were no longer simply subjects of a distant centre; they now fell under a shared legal order. Historians also note that Caracalla was pushing an existing development to its extreme: since the late Republic, more and more groups had been granted citizenship - first in Italy, and later in selected cities around the Mediterranean.

Power, the army and money: what Caracalla was really doing with the Constitutio Antoniniana

The measure can sound progressive, even humanistic - but the motivation was far more hard‑headed. Caracalla ruled an empire under military strain and financial pressure. The army consumed a large share of the public budget, and soldiers were paid ever higher wages to keep their loyalty.

Extending citizenship instantly created millions of new taxpayers. Many levies had previously applied only to citizens; those who were not citizens were exempt. That changed overnight.

With the new citizen status came not only more rights - but also more obligations, especially to the treasury.

One levy was particularly important: a five percent tax on inheritances and legacies. By handing out citizenship on such a scale, Caracalla increased the number of people required to pay it. Contemporary critics therefore accused him of doing less to honour provincial inhabitants than to send them the bill.

There was more at stake, however. The reform also helped produce a more uniform tax system. Rules became more similar across the empire, simplifying administration and oversight - a crucial advantage in territory stretching from Britain to Egypt.

Citizenship, yes - genuine equality, no

Despite the grand gesture, daily life for many newly minted citizens remained ambiguous. In legal terms they were Romans; socially, they were often still treated as second‑class. Local power structures, ethnic distinctions and older customary laws continued to shape realities on the ground.

Formally, the new status brought important safeguards:

• entitlement to an orderly court procedure
• protection from particularly degrading punishments
• the option to challenge verdicts by appealing to the emperor

On paper, this looked like a major step towards equality before the law. In practice, much depended on where someone lived, what background they had and how influential local elites were. In many places, long‑standing legal customs continued alongside Roman law - for example in Egypt or in North Africa.

Another complication was that not everyone who became a citizen gained the same opportunities. Many adopted a Roman name - often “Aurelius”, a nod to Caracalla’s family name - yet still remained distant from local offices and had no access to civic honours. The result was a kind of two‑tier citizenship: everyone was a citizen, but not everyone enjoyed the same room for manoeuvre in society.

One group was excluded entirely: the so‑called dediticii. They were treated as people without full rights, often former enemies in war or freed persons with a special status. Caracalla’s edict did nothing for them. If anything, it made the line between “inside” and “outside” more visible, because the general grant of citizenship highlighted who still remained shut out.

From Roman citizen registers to modern passports

For all its contradictions, Caracalla’s decision laid groundwork for a development that reaches deep into the modern era. As citizenship was standardised, Roman law spread more widely across the empire and gained weight relative to local traditions. That legal culture later influenced medieval and early modern Europe as well.

Several structures we now take for granted still bear traces of that period:

• Passports and identity documents: Anyone who holds a passport or identity card today stands in a tradition of systematic citizen registration. Even in the Roman Empire, citizens had to be identifiable - with clearly defined name and status.
• Full legal name: The Roman pattern of given name, family name and additional name helped inspire later naming systems. The modern idea of a “full legal name” follows a similar logic: linking individuals unambiguously to a state and a legal order.
• Equality before the law: The notion that all citizens stand under the same law appears in Roman law in early forms and continues to shape constitutions worldwide.
• Tax liability as a civic duty: The tight connection between citizen status and tax liability, which Caracalla deliberately exploited, persists in modern tax systems.

Anyone who goes to court today and insists on a fair trial is, without realising it, drawing on a tradition that took political shape in the Imperium Romanum.

What modern states inherited from Rome

If you look closely at today’s states, you repeatedly find ideas that can be traced back to Caracalla’s edict:

• A unified category of citizen: The principle that a state records all its members legally as citizens, rather than maintaining multiple classes of subjects.
• Centralised tax collection: Revenue flows not only locally but into a higher state treasury - coordinated through administration and law.
• Legal harmonisation: Regional differences remain, but core issues - property, inheritance, basic procedural rights - follow a shared line.

Modern revolutions, such as those in France or North America, gave these ideas a new and far more egalitarian direction. Even so, Roman precedents continued to work in the background: citizens’ rights as a blend of protection, obligations and belonging to a wider political whole.

Why an edict from AD 212 still matters now

Current debates about citizenship, dual passports, migration or tax evasion circle around questions very similar to those raised by Caracalla’s edict: Who belongs? Who carries which burdens? What rights must be granted to everyone counted as a citizen?

Keeping that Roman prehistory in mind makes one point clear: citizens’ rights do not emerge in a vacuum. They are the product of political choices, power interests and financial constraints - which is precisely why they are contested. Caracalla’s move shows how a state can use the legal status of its inhabitants to decide who forms part of the “we”.

In practical terms today, that means that behind every passport application, every tax return and every appeal in court sits a very old idea: that people are not merely subjects, but legal persons with enforceable rights. The exact rules have changed, but the core remains: citizenship ties the individual to a state and its order.

Anyone thinking about future reforms to citizenship law or tax law can take several lessons from this history. Expanding citizenship can create more protection and participation, but it can also quickly generate new inequalities. And any change to citizens’ status reaches deep into the relationship between people and the state - so deep that even a decision taken in AD 212 still reverberates today.