People have always needed to talk to someone who isn't in the room. A king wants a distant governor to collect taxes. A merchant needs to tell his partner what the tin is selling for. A woman stuck at a frontier fort wants her friend to come to her birthday party. For most of history the only way to do any of this was to write something down and have it physically carried to the other person. That is correspondence: written messages sent between people who are apart.
This article follows correspondence from the first sealed clay letters of Mesopotamia, through the Persian and Roman courier systems, the letter-writing culture of the Renaissance, and the postal reforms of the nineteenth century, up to the telegraph and email. Along the way it looks at how each change in material, cost and speed changed what people wrote and who got to write at all. It sticks to well-documented collections and dates. Where historians disagree or the record is thin, it says so.
What counts as correspondence?
Correspondence needs three things. First, a way of writing language down. Second, something to write on that can be moved. Third, some way of getting the message from sender to recipient, whether that's a servant, a paid courier, a state relay system or a network of wires.
Each of these has a history of its own, and change in one often forced change in the others. Clay is cheap and lasts well but it is heavy. Papyrus and wood are lighter. Paper became cheap enough for ordinary people to use. Delivery went from favors and private messengers, to state systems open only to officials, to public postal services that anyone could use for a penny. Then came electricity, which separated the message from any physical object carried by hand.
One theme keeps coming back. In nearly every period, the people who could send letters were a small group: rulers, officials, merchants, scholars. Much of the history of correspondence is the story of that group growing larger.
The first letters: cuneiform on clay
Writing first appears in the archaeological record at Uruk in southern Mesopotamia at the end of the fourth millennium BC. The first clear written documents date to about 3300 BC, in what archaeologists call the Uruk IV period. These early tablets are known as proto-cuneiform. Their signs are mostly pictures, and most of the records are accounts: lists of goods, workers and rations. Scholars trace the system back to an older Near Eastern habit of using small clay tokens to keep accounts.
So writing did not start as a way to send messages. It started as bookkeeping. But once scribes could record language, it could also carry instructions, requests and news. Over the following centuries the wedge-shaped script known as cuneiform was used for legal and administrative texts and for letters.
Mesopotamian scribes also invented a simple privacy device: the clay envelope. Starting in the Early Dynastic IIIb period (roughly 2500 to 2340 BC), a letter tablet could be wrapped in a thin outer shell of clay and sealed. To read the letter, the recipient had to break the envelope. This meant they could tell if anyone had opened it on the way. It is an early answer to a problem every postal system since has had to deal with: how do you know nobody read your mail?
The scale of what survives is huge. An estimated half a million cuneiform tablets are held in museums around the world. Estimates of the total excavated run from 500,000 to 2 million, but only about 30,000 to 100,000 have been read or published. Cuneiform stayed in use for a remarkably long time. The latest tablet that can be firmly dated is an astronomical almanac from Uruk from AD 79/80, more than three thousand years after the script's beginnings.
The merchants of Kanesh
The richest early archive of private letters comes from Kültepe, the site of ancient Kanesh in central Anatolia (modern Turkey). There, in the trading quarter of the town, called the kārum, archaeologists have recovered more than 22,000 cuneiform tablets. Sources differ slightly on the exact figure, with some giving over 23,000. Most of them date to the early second millennium BC, with the main occupation level (Level II) dated to roughly 1945 to 1835 BC.
The texts are written in Old Assyrian. They were left by Assyrian merchants who settled at Kanesh and traded tin and wool for goods coming from Assyria and Elam. Importantly, this trade was run by families, not by the state. So the letters show businesses run between Assur, the home city, and Anatolia: prices, debts, shipments and quarrels. Some of the tablets are still inside their clay envelopes, stamped with cylinder seals.
What makes Kanesh especially valuable is that women wrote many of the letters. Women such as Taram-Kubi and Zizizi ran businesses and wrote to their husbands, who were often away trading. The archive also preserves Hittite names and loanwords, which are the oldest recorded traces of any Indo-European language. Here, almost four thousand years ago, correspondence is already doing what it would do for the rest of history: holding families and businesses together across distance.
Diplomacy by letter: the Amarna letters
A few centuries later, clay letters were running international politics. Around 1887, local Egyptians digging at el-Amarna, the site of the pharaoh Akhenaten's short-lived capital Akhetaten, found a cache of cuneiform tablets. Today 382 tablets and fragments are known. About 350 are letters, and the rest are literary and school texts that scribes used for training.
The letters date to the mid-fourteenth century BC and cover at most about thirty years, possibly as few as fifteen. On the Egyptian side the main figures are the pharaohs Amenhotep III and Akhenaten and their officials. Writing to them were the great kings of the age, the rulers of Babylonia, Assyria, Mitanni, Hatti, Arzawa and Alashiya (Cyprus), as well as many smaller rulers in Canaan and Syria. These included Rib-Hadda of Byblos, Abdi-Heba of Jerusalem and Aziru of Amurru.
One detail tells you a lot about how international correspondence worked then. Most of the letters are written not in Egyptian but in a form of Akkadian, the shared diplomatic language of the time. The scribes' own Canaanite speech often shows through. One long letter, known as EA 24, is in Hurrian. So a pharaoh needed a staff of trained foreign-language scribes just to read his mail.
The tablets are now scattered. Roughly 200 are in Berlin's Vorderasiatisches Museum, about 99 at the British Museum, around 50 in Cairo, and smaller numbers in the Louvre, Moscow, Chicago, Oxford and Brussels. The standard edition was published by the Norwegian scholar Jørgen Knudtzon in 1907 and 1915.
Relay roads: the Persian and Roman courier systems
Writing a letter is one problem. Getting it there is another. The great early empires solved this with state-run relay systems.
In the Achaemenid Persian Empire, Cyrus the Great set up a relay courier system that Darius the Great later expanded. It is often called the Chapar Khaneh. Its stations lay mainly along the Royal Road between Sardis in the west and Susa in the east. They were spaced about a day's ride apart, so a fresh horse and rider were always waiting. Using these relays, a message could cover about 2,700 kilometers in roughly nine days, far faster than anyone could walk it.
The Greek historian Herodotus described the system around 440 BC. His praise of the couriers is usually rendered in English as "Neither snow nor rain nor heat nor gloom of night." That line is now carved on the James A. Farley Building in New York City, a former main post office. It is often taken to be the official motto of the U.S. Postal Service, but it is really an inscription borrowed from a Greek description of a Persian institution.
Rome built its own version. Emperor Augustus created the cursus publicus, a state courier and transport service that moved messages, officials and tax revenue between Italy and the provinces. Augustus changed the Persian model in one important way. Instead of passing a message from rider to rider, he had a single courier make the whole journey. That way the messenger could be questioned on arrival about what he had seen and heard.
The service ran along the main Roman roads. Mutationes were relay points where you could change animals and make repairs. Mansiones also offered lodging. Normal travel covered roughly 38 to 62 miles a day, and urgent messages could go faster. It was never a public mail service, though. Only the government and military could use it freely, and anyone else needed an imperial travel permit called a diploma. It was expensive to run. Under Nerva in the late first century the cost was shifted to the imperial treasury, and Hadrian later put it under a prefect. The system kept working in the Eastern Empire into the sixth century before shrinking. The historian Procopius accused Justinian of dismantling most of its routes.
Ink, wood and papyrus: letters in the Greco-Roman world
Clay works well in a dry climate where it is abundant. Around the Mediterranean, people wrote on lighter materials, and some of them have survived in unlikely places.
Oxyrhynchus: an ancient rubbish dump
In the winter of 1896–97, two young Oxford scholars, Bernard Grenfell and Arthur Hunt, began digging at the ancient rubbish dumps of Oxyrhynchus in Egypt (modern el-Bahnasa). Egypt's dry sand had preserved enormous quantities of discarded papyrus. The documents date from the Ptolemaic period in the third century BC, and through Roman rule from 32 BC up to the Muslim conquest of Egypt in AD 640.
The finds include literature and scripture, and also the ordinary paperwork of a provincial town: contracts, court records, and private letters. Since 1898 scholars have transcribed and published over 5,000 documents. That is thought to be only 1 to 2 percent of at least half a million papyri still waiting to be conserved and read. The publication series is still going, with volume 88 released on 1 May 2025. A large share of the collection is at Oxford's Bodleian libraries.
Vindolanda: letters from the edge of the empire
At the other end of the Roman world, in northern England, letters survived for a different reason: waterlogged, oxygen-free soil. In March 1973, the archaeologist Robin Birley was excavating the Roman fort of Vindolanda, near the later line of Hadrian's Wall. A student excavator, Keith Liddell, drew his attention to some thin slivers of wood. They turned out to be letters.
The Vindolanda tablets are thin, postcard-sized leaves of local birch, alder and oak, written in carbon-based ink, then scored and folded. They date from the late first and early second centuries AD, most from before about 105. They are described as the first known surviving examples of ink letters from the Roman period. More than 1,700 had been found by 2023, and most are now in the British Museum.
The contents are refreshingly ordinary. One letter (tablet 343) from a man named Octavius to Candidus deals with supplies of wheat, hides and sinews. Another (tablet 346) mentions underpants among a parcel of items sent to a soldier. The most famous, tablet 291 from around AD 100, is a birthday invitation from Claudia Severa to her friend Sulpicia Lepidina. It is one of the earliest known examples of Latin written by a woman. Two officers' wives on a cold frontier, organizing a party by letter, is about as human as ancient history gets.
Cicero and the literary letter
Roman elites also treated letters as something worth keeping and reading later. The orator and politician Marcus Tullius Cicero is the outstanding example. Of his 813 surviving letters, 454 are addressed to his close friend Titus Pomponius Atticus, written between 68 and 43 BC. They are frank and personal, and together with his other letters they are considered among the most reliable sources for the years leading to the fall of the Roman Republic.
Cicero's letters also show how fragile correspondence archives are. The letters to Atticus seem not to have been published until the mid-first century AD, long after both men had died. The collection was then largely lost to Western Europe until 1345, when the Italian poet Petrarch found a manuscript in the chapter library of Verona and had it copied. Both that manuscript and Petrarch's copy are now lost too. The text spread widely only after Paolo Manuzio printed an edition in Venice in 1558. Petrarch's find was one spark of a wider Renaissance enthusiasm for letter-writing modeled on classical authors.
Letters in late medieval England: the Pastons
As paper spread in Europe in the later Middle Ages, letter-writing moved beyond courts and monasteries into the households of the gentry. The best-known English example is the Paston letters. This is a collection of correspondence and papers of the Paston family of Norfolk, running from 1422 to 1509.
The family's rise is itself a story. William Paston (1378–1444) became a Justice of the Common Pleas in 1429. His son John Paston I married Margaret Mautby, and many of the most vivid letters come from Margaret and from her sons John II and John III. The letters cover property disputes, lawsuits, household management and the dangers of the Wars of the Roses. They also include love letters. Richard Calle wrote to Margery Paston. Margery Brews wrote Valentines to John Paston III.
The letters matter to historians for what they say about fifteenth-century life. They matter to linguists because they were written during the shift from Late Middle English to Early Modern English, including the Great Vowel Shift, and they preserve everyday, colloquial language. James Gairdner's complete edition of 1904 contained 1,088 letters and papers. A newer edition by Norman Davis appeared in 1971 and was revised by Richard Beadle and Colin Richmond in 2004. Most of the originals are in the British Library, with others in Oxford and Cambridge.
The Paston letters also had their own authenticity scare. After the first editor, John Fenn, published selections in 1787 and 1789, his manuscripts disappeared. In 1865 the writer Herman Merivale questioned whether the letters were genuine. Gairdner defended them, and the originals were later found in several places.
The Republic of Letters
Between the Renaissance and the Enlightenment, letters became the main way scholars across Europe shared ideas. People at the time called this community the "Republic of Letters." The earliest known use of the Latin phrase respublica literaria is in a letter from the Venetian humanist Francesco Barbaro to Poggio Bracciolini, dated 6 July 1417. The French philosopher Pierre Bayle made the term well known in his journal Nouvelles de la République des Lettres, started in 1684.
The Republic of Letters had no borders or government. It was a network of scholars who wrote to each other, passed letters on, and circulated copies. Over time some of this exchange became formal. Henry Oldenburg, secretary of the Royal Society of London, edited its Philosophical Transactions, one of the first scientific journals. Learned journals like it gave the scholarly exchange of the Republic of Letters a printed, public form.
Building postal networks
None of this scholarly exchange would have worked without regular ways of moving letters. From the sixteenth century, European states and private operators built them.
In the Holy Roman Empire, the Taxis family (later Thurn und Taxis) served as imperial couriers during the sixteenth century. The office of Imperial Postmaster General became hereditary in the family in 1615. Their network suffered heavy losses during the French Revolutionary and Napoleonic Wars. After the Holy Roman Empire was dissolved in 1806, the family carried on as a private postal operator, the Thurn-und-Taxis Post, based first in Regensburg and later in Frankfurt. It issued its own stamps from 1852. After Prussia won the Austro-Prussian War, the family's postal rights were sold to Prussia for three million thaler, and control passed on 1 July 1867. A family business had carried a large part of central Europe's mail for over two centuries.
In British North America, Benjamin Franklin became postmaster of Philadelphia in 1737 and joint postmaster general for the colonies from 1753 to 1774. He improved service with surveyed routes, overnight travel between New York and Philadelphia, and a standard rate chart. In 1775 the Continental Congress made him the first Postmaster General. After independence, President George Washington signed the Postal Service Act on 20 February 1792, which established the U.S. Post Office Department. The act set letter postage at 6 to 25 cents depending on distance, and gave newspapers very cheap rates of 1 cent up to 100 miles and 1.5 cents beyond. Printers could also swap papers with each other free of charge. That newspaper subsidy is an early example of a government deliberately using the post to spread public information.
The penny post revolution
Before 1840, sending a letter in Britain was expensive and confusing. Postage depended on the distance a letter traveled and how many sheets of paper it used, and it often cost more than four pence. Payment was usually made by the recipient, not the sender, because prepaying was optional.
Rowland Hill argued that this was the wrong way round. He put his ideas to a government commission on 13 February 1837 and published them that year as a pamphlet, Post Office Reform: its Importance and Practicability. In 1838 he proposed a uniform rate of one penny per half ounce for letters anywhere in the British Isles, regardless of distance, paid in advance by the sender. Parliament adopted the idea in the Post Office (Duties) Act 1840, which created the Uniform Penny Post.
To make prepayment easy, Britain issued the world's first adhesive postage stamp, the Penny Black. It was first issued on 1 May 1840 and became valid for use on 6 May. It shows a profile of the young Queen Victoria, engraved by Charles and Frederick Heath from a sketch by Henry Corbould, which was based on an earlier head by William Wyon. In total, 68,808,000 Penny Blacks were printed, and an estimated 1.3 million survive. At the same time the Post Office issued pre-printed letter sheets designed by the artist William Mulready. The public loved the stamps and ridiculed the Mulready sheets.
The results showed how much demand had been held back by price. The number of letters sent in the UK more than doubled in 1840, the first year of the penny post, and doubled again within about ten years. Cheap, prepaid, flat-rate postage turned letter-writing from something the better-off did when necessary into an everyday habit for millions of people. Postal systems in many other countries soon followed.
Speed versus wires: the Pony Express and the telegraph
In the middle of the nineteenth century, the pressure was on speed. The United States offers a good example of how fast the ground shifted.
The Pony Express began on 3 April 1860 at St. Joseph, Missouri. Riders carried mail about 1,900 miles to Sacramento, California, changing horses every 10 to 15 miles at roughly 190 stations. Mail could cross the continent in about ten days. It became a legend, but it was a financial failure. It grossed about $90,000 and lost about $200,000 despite a government subsidy. Its closure was announced on 26 October 1861, only about eighteen months after it started. Just two days before that announcement, the transcontinental telegraph had been connected.
The telegraph had been developing for over two decades by then. In Britain, William Fothergill Cooke and Charles Wheatstone patented their needle telegraph in May 1837. In 1838 it went into commercial use on the Great Western Railway between Paddington and West Drayton. In the United States, Samuel Morse sent the message "WHAT HATH GOD WROUGHT" from the Capitol in Washington to Baltimore on 24 May 1844.
Crossing oceans was harder. Attempts to lay a transatlantic cable in 1857, 1858 and 1865 did not produce a lasting link. The 1857 cable worked only on and off for a few days or weeks. A durable cable was finally completed on 18 July 1866, laid by the giant steamship Great Eastern. By the late 1800s, most developed countries had commercial networks that let anyone send a telegram to anywhere in the country for a fee.
The telegraph changed the nature of correspondence. For the first time, a message didn't have to travel as a physical object. A telegram was still delivered on paper at the far end, but what traveled between cities was electrical signals. Because telegrams were charged by the word, they produced their own terse style. Letters, meanwhile, stayed the medium for anything long, personal or detailed.
Letters go global: the UPU and the postcard
As more countries built national postal services, sending mail across borders was still a tangle of separate bilateral deals and rates. In 1874 the German Postmaster-General, Heinrich von Stephan, called an international congress in Bern, Switzerland. On 9 October 1874 the Treaty of Bern created the General Postal Union, renamed the Universal Postal Union (UPU) in 1878.
The treaty set some simple rules. There would be a uniform flat rate for international letters. Foreign and domestic mail would be treated the same. Each country would keep the postage it collected, instead of trying to share it out piece by piece. The UPU has been a specialized agency of the United Nations since 1948, is still based in Bern, and has 192 members. The day of its founding, 9 October, is a reminder that the global mail system was a deliberate act of international cooperation, not something that just happened.
Around the same time, a new and cheaper form of correspondence appeared: the postcard. Its origins are disputed. The writer Theodore Hook is credited with sending himself a hand-painted caricature card in 1840, probably as a joke. It sold at auction for £31,750 in 2002. In the United States, Hymen Lipman produced a "Lipman's Postal Card" in 1861. The first official postcard came in Austria-Hungary. In October 1869 the post office accepted a proposal by Emanuel Herrmann for a cheap card without an envelope. Three million were mailed in the first three months.
Picture postcards boomed between about 1890 and 1915, peaking around 1907 to 1910. They made correspondence quick, public (anyone handling the card could read it) and visual. In some ways they were the short social media posts of their day.
Email and the digital letter
The next big change came from computers. Once time-sharing systems in the early 1960s let many people use one machine, it became possible for users of the same computer to leave messages for each other. A well-known early example ran on MIT's Compatible Time-Sharing System (CTSS) in 1965.
The leap to messages between different computers came in 1971. Ray Tomlinson, an engineer at the firm Bolt, Beranek and Newman (BBN), adapted a program called SNDMSG. It let users leave messages for others on the same machine, and Tomlinson combined it with code from CPYNET, a file-transfer program he had written, so messages could go across the ARPANET to users on other computers. To separate the user's name from the name of their computer, he chose the @ sign, because it wasn't used in usernames and its meaning ("at") was clear. That user@host format is still how email addresses work.
The first network messages were tests between two machines sitting side by side. Tomlinson later said, "The test messages were entirely forgettable and I have, therefore, forgotten them." The popular claim that the first email said "QWERTYUIOP" is a misquote of his guess that it was something like that.
Email was standardized over the next decade. RFC 822, published in 1982, became the Internet standard for message format for about twenty years, and SMTP, the protocol for sending mail, went into use on the ARPANET in 1983. Growth was enormous. By 2011 there were an estimated 1.4 billion email users and about 50 billion non-spam emails sent every day. Spam became a major problem, with estimates suggesting most email traffic is unwanted.
Email kept many conventions of the paper letter: the salutation, the sign-off, the subject line (a cousin of the old reference line), and the idea of an inbox. It also removed things. There is no cost per message, no wait of days or weeks, and no physical object. With the costs gone, volume exploded, and the old problems of trust and privacy came back in new forms. The clay envelope that showed whether a letter had been opened has digital successors in encryption and digital signatures.
What the long history shows
Looking across five thousand years, a few patterns stand out.
Cost decides who writes. Clay letters needed trained scribes. The Roman cursus publicus served the state. Before 1840, British postage was expensive enough to keep many people from writing. Each drop in cost, from Rowland Hill's penny post to the near-zero cost of email, brought huge numbers of new writers in and produced a jump in volume.
Speed changes the form. Letters that took weeks could be long and considered. Telegrams charged by the word became clipped. Email and its successors are faster and usually shorter again.
Privacy is a constant worry. Sealed clay envelopes, wax seals, and later encryption are all answers to the same question of whether the message reached its reader unseen.
Survival is luck. The letters we have survived because of dry sand at Oxyrhynchus, waterlogged soil at Vindolanda, a family that kept its papers in Norfolk, or a poet who happened to look in a cathedral library in Verona. For every surviving letter, countless others are gone. Historians of the future may face the opposite problem: far too much digital correspondence, much of it stored in formats and services that may not last.
Letters are ordinary. The most moving survivals are often the most everyday: a merchant's wife in Kanesh writing about business, a Roman officer's wife sending a party invitation, a Norfolk gentlewoman managing an estate in wartime. Correspondence lets us hear people who never wrote history books.
Frequently asked questions
What is the oldest known letter? There is no single agreed "first letter." Writing appears in Mesopotamia around 3300 BC, mostly as accounts. Cuneiform was later used for letters, and sealed clay envelopes for them appear by roughly 2500 to 2340 BC. Large archives of letters, such as those from Kültepe (early second millennium BC), come later.
What are the Amarna letters? They are about 350 diplomatic letters on clay tablets from the mid-fourteenth century BC, found around 1887 at el-Amarna in Egypt. They were exchanged between the pharaohs Amenhotep III and Akhenaten and other rulers of the Near East, mostly in Akkadian.
Is "Neither snow nor rain..." the official motto of the U.S. Postal Service? Not officially. The phrase comes from Herodotus's description of Persian royal couriers, written around 440 BC. It is carved on the James A. Farley Building in New York, a former main post office, which is why many people associate it with the USPS.
Who invented the postage stamp? The first adhesive postage stamp was Britain's Penny Black, issued on 1 May 1840 and valid from 6 May, as part of Rowland Hill's Uniform Penny Post reform.
Who sent the first email? Messages between users of the same computer existed by the mid-1960s, for example on MIT's CTSS in 1965. Ray Tomlinson at BBN sent the first network email between different computers on the ARPANET in 1971 and introduced the @ sign in addresses. The text of the first message was not preserved.
What is the Universal Postal Union? It is an international organization founded by the Treaty of Bern on 9 October 1874 to coordinate international mail. Since 1948 it has been a United Nations specialized agency, based in Bern, with 192 members.
Sources and further reading
- Wikipedia, "Cuneiform": https://en.wikipedia.org/wiki/Cuneiform
- Wikipedia, "Kültepe texts": https://en.wikipedia.org/wiki/Kültepe_texts
- Wikipedia, "Amarna letters": https://en.wikipedia.org/wiki/Amarna_letters
- Wikipedia, "Angarium" (Achaemenid relay post): https://en.wikipedia.org/wiki/Angarium
- Wikipedia, "Cursus publicus": https://en.wikipedia.org/wiki/Cursus_publicus
- Wikipedia, "Oxyrhynchus Papyri": https://en.wikipedia.org/wiki/Oxyrhynchus_Papyri
- Wikipedia, "Vindolanda tablets": https://en.wikipedia.org/wiki/Vindolanda_tablets
- Wikipedia, "Letters to Atticus": https://en.wikipedia.org/wiki/Letters_to_Atticus
- Wikipedia, "Paston Letters": https://en.wikipedia.org/wiki/Paston_Letters
- Wikipedia, "Republic of Letters": https://en.wikipedia.org/wiki/Republic_of_Letters
- Wikipedia, "Thurn-und-Taxis Post": https://en.wikipedia.org/wiki/Thurn-und-Taxis_Post
- Wikipedia, "Postal Service Act": https://en.wikipedia.org/wiki/Postal_Service_Act
- Wikipedia, "Uniform Penny Post": https://en.wikipedia.org/wiki/Uniform_Penny_Post
- Wikipedia, "Penny Black": https://en.wikipedia.org/wiki/Penny_Black
- Wikipedia, "Pony Express": https://en.wikipedia.org/wiki/Pony_Express
- Wikipedia, "Electrical telegraph": https://en.wikipedia.org/wiki/Electrical_telegraph
- Wikipedia, "Universal Postal Union": https://en.wikipedia.org/wiki/Universal_Postal_Union
- Wikipedia, "Postcard": https://en.wikipedia.org/wiki/Postcard
- Wikipedia, "Email": https://en.wikipedia.org/wiki/Email
- Wikipedia, "Ray Tomlinson": https://en.wikipedia.org/wiki/Ray_Tomlinson