The History of Identity Documents — A 3-Part Series

• Part 1: From Ancient Identity Records to Medieval Passports (current)
• Part 2: When Governments Started Recording Faces
• Part 3: From Genealogy to Digital Databases

The History of Identity Documents, Part 1: From Ancient Identity Records to Medieval Passports

In 445 BC, an official who served wine in the court of the Persian king Artaxerxes I made an unusual request of his sovereign. He asked to be allowed to go to Jerusalem to rebuild its walls. The king agreed, and handed him a bundle of letters — travel permits addressed to the governors west of the Euphrates River, instructing every official in every territory he would need to cross to let this man pass safely.^[1]

That official’s name was Nehemiah. This scene, recorded in the Book of Nehemiah in the Old Testament, is considered the earliest known passport record.^[2] But in all likelihood, the passport was not a new invention at this point. The ease with which the king wrote the letters suggests that travel permits were already a long-established administrative practice.

The demand to “prove who you are” is as old as the state itself. To collect taxes, conscript armies, prevent enslaved people from escaping, and keep track of foreigners, ancient states each invented their own methods of confirming identity. And those methods bear a remarkable resemblance to the modern identity card.

Mesopotamia: Identity on Clay Tablets

In ancient Mesopotamia, identity verification was inseparable from trade. When a merchant needed to carry goods to another city, they were required to carry a clay tablet bearing the signature of an official at their point of origin. This document recorded the merchant’s name, a list of goods, and their destination.^[3]

The city-states of Sumer and Babylon had systematic documentary administration as far back as 3000 BC. Recording the movement of goods and people was part of the bookkeeping required to manage royal storehouses. When you consider that writing itself was originally invented for this very purpose, the history of identity verification and the history of writing can be said to have grown from the same root from the very beginning.

Ancient Egypt operated a similar system. To track the population of the Nile River basin and manage taxes and labor, the pharaoh’s officials conducted censuses. Records from the reign of Pharaoh Amasis around 570 BC are among the oldest known census documents, recording population counts, occupations, and property.^[4] The use of papyrus and seals as means of identity verification in Egypt shows that the origins of identity records are almost contemporaneous with the birth of civilization itself.

Rome’s Bronze Identity Documents: Military Discharge Certificates

The Roman Empire left a particularly noteworthy example in the history of identity verification: the bronze identity certificate known as the diploma militare — a military discharge certificate.

The Roman army recruited large numbers of provincial subjects without citizenship as auxiliaries. Gauls, Syrians, North Africans, Dacians, and others served for 25 years guarding the empire’s borders. What they received upon discharge was a certificate made of two bronze plates.^[5]

This certificate was no mere memento. The soldier who received it acquired Roman citizenship — a status that carried real privileges, including tax reductions and legal protections. The two bronze plates bore identical content, with the inner text also readable from the outside. Seven witnesses’ names and seals were added, so that in the event of forgery, the sealed inner content could be compared with the outer text.^[5]

The oldest known military discharge certificate was issued in AD 52, during the reign of Emperor Claudius.^[5] Records of near-annual issuance survive through the mid-2nd century. When Emperor Caracalla granted citizenship to all free people of the empire in 212 AD, the need for these certificates disappeared — but for the roughly 150 years before that, Rome’s military discharge certificates were effectively the first mass-issued identity documents.

The Romans also used another identity verification tool called the tessera hospitalis — a “guest token.” When two families formed a long-standing bond, they would split a small token made of clay or wood, each keeping half. Much later, when a descendant of one family visited the other, presenting that half would earn them a welcome as a guest, even as a stranger.^[6] Just as modern identity documents are checked against a database, Romans verified identity by matching the pieces together.

China’s Hukou System: The World’s First Systematic Population Registration

In China, the history of identity records stretches back to the Zhou Dynasty (1046–256 BC). At that time, travelers wishing to pass through checkpoints needed two documents: a jié, a small token made of jade or bronze, and a zhuàn, a piece of bamboo recording the traveler’s name, travel purpose, and stops along the way.^[7] Passing through a checkpoint without these documents meant arrest.

However, it was during the 4th century BC that China’s identity record system acquired its fully systematic form, at the hands of the Qin state reformer Shang Yang. Shang Yang introduced a joint-liability household registration system, grouping five households into one wǔ and ten households into one shí. If one household committed a crime, the other households in the same group were also punished.^[8] This was not mere population tracking. It was a mechanism of social control that made people watch one another.

Shang Yang’s reforms helped make the Qin state the most powerful during the turbulent Warring States period. When Qin unified China in 221 BC, this household registration system spread across the country. The Han Dynasty added the hùlǜ — a household legal code — to formally codify household registration as the legal basis for taxation and military conscription.^[8]

During the Han period, a travel permit called the guòsuǒ also appeared for passing through checkpoints. Recorded on bamboo strips, this document listed the traveler’s identity, destination, and purpose of travel, and had to be inspected at each checkpoint.^[7] Those with unpaid taxes or unresolved legal disputes could not obtain a permit — a situation remarkably similar to modern passport denial.

Under the Tang Dynasty (618–907 AD), this system became even stricter. Moving without a permit meant forced labor as punishment. The monk Xuanzang, who set out to retrieve Buddhist scriptures from India, crossed the border secretly without a permit — one of the most famous undocumented migrants in history. After returning from India, he received a retroactive pardon through imperial special amnesty.^[7]

Joseon’s Hopae and Mapae: Badges That Revealed Social Rank

In 1413, more than twenty years after the dynastic transition from Goryeo to Joseon, King Taejong launched the most ambitious population management project in Joseon history. He issued a decree requiring all males aged sixteen and over to carry a hopae — an identity tag.^[9]

The hopae functioned like today’s national identity card. The tag bore the holder’s name, birth year, place of origin, and social status. But in Joseon, the hopae went beyond simple identity verification — it was a tool that physically revealed social rank. High-ranking yangban officials carried tags made of ivory. Lower-ranking yangban carried tags of horn. Commoners received wooden tags, while servants and those of the lowest status received tags of coarser material.^[9]

Yet the system was abolished just three years after its introduction, in 1416.^[9] The official reason was that new household registers had been completed, making the hopae no longer necessary — but in reality, strong resistance from commoners who objected to being required to carry the tags also played a role. There was considerable psychological resistance to always carrying a tag marked with one’s social rank. The system was subsequently revived and abolished multiple times.

Joseon also had another kind of identity document with a different character: the mapae. The mapae was a bronze badge that authorized officials on official travel to borrow horses at post stations along the road.^[10] Looking at mapae held in the National Museum of Korea, the number of horses engraved on the badge indicates the official’s rank and the number of horses they could borrow. One horse meant a low-ranking official; ten horses indicated a member of the royal family.

The mapae was also the symbol of the amhaeng-eosa — the secret royal inspector. The scene of a secret inspector exposing local corruption and then revealing the mapae while declaring “The royal inspector appears!” became an enduring symbol of authority throughout the Joseon period. A single mapae represented the king’s authority itself.

The Islamic World’s Tax-Receipt Passport

The Islamic Caliphate (632–1258 AD) adopted a distinctive approach that linked identity verification to tax administration. The document known as the barā’a was a tax payment receipt.^[11]

Muslims paid zakāt (religious tax), and non-Muslims paid jizya (a head tax); both received this receipt upon payment. To travel between regions within the caliphate’s territory, this receipt had to be presented at checkpoints. Those who had not paid taxes could not travel. The tax payment receipt was the travel permit.^[11]

This system closely resembles the logic of the modern state: only citizens who have fulfilled their obligations to the state are entitled to use the state’s infrastructure. In the case of the Islamic Caliphate, that obligation was tax payment, and that infrastructure was roads and borders. In the medieval Islamic world, taxes and freedom of movement were a single package.

Medieval Europe’s Travel Permits: Letters from Sovereigns

In medieval Europe, long-distance travel always carried danger for merchants, pilgrims, and diplomats alike. A traveler without the protection of a king or lord was easy prey for bandits or local lords extracting tolls. The solution was the “safe-conduct” letter.

A safe-conduct was a letter issued by a king or lord, commanding that “the bearer of this letter be allowed safe passage,” with the king’s seal guaranteeing its authority. In England, records survive of Henry II issuing such safe-conducts to Cologne merchants as early as the 1100s.^[12]

The English Parliamentary Act of 1414, enacted during the reign of Henry V, codified this practice into law. This act is often described as the “first passport law,” but in fact its core content was not the introduction of passports — it was that violations of safe-conducts would be punished as treason.^[12] In other words, the safe-conduct itself had been standard practice for centuries; the 1414 act simply reinforced its legal force.

The word “passport” itself derives from the Latin passus (passage) and portus (harbor, gate). The first appearance of the word in official English documents came in 1540, when the Privy Council under Henry VIII began issuing travel documents.^[12]

In the Crown of Aragon-Catalonia, a safe-conduct called the guidaticum enabled trade among Christian, Jewish, and Muslim merchant communities.^[12] The fact that these three religious communities moved and traded within the same documentary system illustrates just how complex and multilayered the identity authentication system of the medieval Mediterranean world needed to be.

A Common Logic, Different Solutions

From ancient Egypt’s papyrus records to Rome’s bronze discharge certificates, China’s bamboo travel permits, Joseon’s hopae, Islam’s tax payment receipts, and medieval Europe’s safe-conducts — the forms were different, but all these systems tried to solve the same problem: “Is this person who we know them to be? Does this person have the right to be here?”

What is striking is the difference in the solutions each society adopted. Rome engraved in bronze to prevent forgery. China made collective surveillance operate through joint liability. Joseon visualized class through material differences. The Islamic Caliphate bound tax payment and the right of movement together as one. European monarchs relied on the symbolic authority of the royal seal.

Yet the premise under which these systems operated was broadly similar. It was generally the socially vulnerable who were required to prove their identity. Rome’s discharge certificates were for soldiers of non-citizen origin. Joseon’s hopae placed a far heavier burden on commoners than on yangban. China’s travel permits were designed to catch those evading taxes and corvée labor. The Islamic barā’a was a means of enforcing tax payment. The history of identity verification systems is also a history of how states have controlled the movement of their people for their own purposes.

As modernity arrived, this logic became more refined and more pervasive. Until the invention of attaching a photograph to paper entirely transformed the way identity was confirmed, people still had to prove who they were in unfamiliar lands.

Next article: Part 2: When Governments Started Recording Faces