They Read a 4,000-Year-Old Letter Without Opening It

Source trail

Claim → sources → boundary

Research

ENCI study

CT exposes the writing; Cécile Michel reads and translates the Old Assyrian texts. The paper reports selected readable objects, not universal success.

Object records

Three named letters

Kt 94/k 1150, Kt 94/k 602 and Kt 93/k 144 connect the translations with object metadata and processed scan files.

Boundary

Messages, not confirmed outcomes

Anna-anna reports a debt dispute. Two tablets share an envelope but their textual relationship is unclear. The cancellation letter discusses a separate contract.

The 4,000-year-old letter read without opening it was still in its clay envelope at a museum in Ankara, Türkiye. In it, a woman named Anna-anna described her attempts to collect silver owed to her husband. The debtor would not pay her. The research team's published translation lets us read her account while the envelope remains intact, with her seal still impressed into its surface.

That envelope already named the sender and recipient. What the scan added was the message they could not see.

Short version

Researchers used ENCI, a transportable X-ray computed tomography scanner, to reveal writing on cuneiform tablets sealed inside clay envelopes. Software reconstructed and separated the surfaces digitally; Assyriologist Cécile Michel read and translated the texts. The 2026 study in npj Heritage Science includes Anna-anna's letter, Kt 94/k 1150, from Kültepe, ancient Kanesh, in central Türkiye. It concerns recovering a debt of silver. Reading it without breaking the envelope preserves the seals and the physical relationship between the message and its covering.

Source trail at a glance

• ENCI research paper: Scanner design, reconstruction method, translations and the limits of separating touching clay surfaces.
• Kt 94/k 1150 dataset: Anna-anna's letter, its excavation number, translation, photographs and reconstruction files.
• Kt 94/k 602 dataset: A letter with a main tablet and a smaller supplementary tablet inside one envelope.
• Kt 93/k 144 dataset: A letter giving instructions about cancelling a separate investment-loan contract.
• University of Hamburg account: A plain-language explanation from the institution involved in the research.

The companion source guide groups these records by the question each can answer.

The ancient tablets are primary evidence of the messages their writers sent. The paper reports the modern imaging work and supplies scholarly readings of those messages. The university account explains that research; it is not a separate ancient witness.

How a CT scanner reads through a clay envelope

The writing is impressed into clay, rather than written in ink on a page. Researchers need to recover the tablet's surface and the shapes of its wedge marks.

ENCI records X-ray images as the object rotates. A computer reconstructs a three-dimensional volume, and further software identifies the clay surfaces. Researchers can then examine a digital tablet with its digital envelope removed. The paper's methods and Figure 5 show the steps between the scan data and the readable model.

This separation is difficult where the envelope touches the tablet. A narrow air gap helps distinguish them, but some parts have no gap at all. The software has to deal with those contacts. In the published image of Anna-anna's letter, white patches mark estimated areas where the envelope touches the tablet. A reconstruction is a processed view of the object, not an ordinary photograph of an exposed surface.

The scanner also had to reach the collection. The technical account describes a machine weighing about 420 kilograms that comes apart into eight components. That made it possible to carry the equipment into museum spaces a conventional large scanner could not reach. Mobile, here, means transportable and assembled on site, not handheld.

The Ankara campaign took place over three weeks beginning in mid-September 2024. Researchers recorded 64 tomograms of 48 tablets and other objects, according to the paper's results section. Those are scanning totals, not a claim that 48 sealed letters were fully translated. The research appeared in 2026.

Why keep the envelope?

Breaking an envelope can give access to a text while destroying other evidence. The study's introduction describes earlier openings that irreparably damaged seal impressions. The authors say these envelopes have no longer been opened for several decades.

Letter envelopes protected tablets during transport, concealed their contents and carried the sender's seal. In Anna-anna's case, the envelope preserves eight impressions of her cylinder seal, alongside the address. Those impressions belong to the history of this particular message. They are not disposable packaging.

The scans also let researchers study how the clay was put together. The section on shaping envelopes reports multiple layers in the scanned envelopes. The authors suggest that layering could make an envelope stronger and help it dry without cracking, but say further experiments are needed. The layers are an observation; the explanation for their advantages remains a proposal to test.

Anna-anna's letter: Kt 94/k 1150

The team identifies Kt 94/k 1150 as a letter excavated in the house of Šalim-Aššur in the lower town of Kanesh. The paper dates it to the first half of the nineteenth century BCE. Its envelope reads, in the published translation:

To Ennum-Aššur, son of Šalim-Aššur. Seal of Anna-anna.

Ennum-Aššur was Anna-anna's husband and a merchant who travelled through central Anatolia. According to the letter's translation and the researchers' interpretation, he had asked her to recover silver he had lent to a colleague.

Anna-anna says she repeatedly approached Laqēpum. He initially claimed to have paid the silver to Kudātum. She challenged that account and threatened to obtain witnesses if he had not paid. He then refused to give the silver to her, saying he would pay Ennum-Aššur when he returned.

It is a specific account of a woman handling business while her husband was away. It also records resistance to her attempt to collect. Neither detail should disappear into a general claim that ancient women were excluded from commerce or enjoyed equal authority in it. This letter gives us Anna-anna's report of one dispute. It does not tell us whether she eventually recovered the money.

The University of Hamburg release says the letter probably never reached her husband. Its closed state supports the researchers' interpretation that it was not read by its intended recipient. We do not know the precise reason it remained undelivered.

A second tablet inside the same envelope: Kt 94/k 602

A bulge in another envelope suggested that it contained more than one tablet. The CT reconstruction of Kt 94/k 602 confirmed a main tablet and a smaller supplementary tablet placed against it.

The main letter concerns textiles, two black donkeys, transport costs and silver to be sent back with a caravan. The smaller tablet asks for a decision about textiles. The authors caution that its text is not clearly linked to the main tablet's text, even though both were enclosed together.

That distinction is useful. The scan establishes their physical association. It does not settle every question about the relationship between their messages. The paper explains that loose supplementary tablets are often difficult to match to their main tablets once an envelope has been opened. Here the original arrangement survives, and the object's dataset lists separate geometry files for both tablets.

A letter about cancelling a contract: Kt 93/k 144

Kt 93/k 144 concerns an enveloped contract for an investment loan of 5 minas of silver. Its writers instruct their correspondents to give the tablet to the relevant person so that he can cancel it.

The scanned object is a letter about that contract, not the loan contract itself. The paper's discussion of cancellation explains that, when a debt was repaid, the creditor returned the document and the debtor cancelled it by breaking its envelope.

For a letter, opening the envelope allowed someone to read the message. For the contract described here, breaking the envelope had a legal purpose. Calling every object a sealed letter without checking its text would miss that difference. The instruction also does not prove that its recipients carried out the cancellation.

What the research does, and does not, establish

The study demonstrates that ENCI and its processing software can make selected sealed texts readable while leaving their clay envelopes physically closed. Its value includes access to the writing, the arrangement of objects inside an envelope and evidence about manufacture.

It is not the first use of CT to examine enclosed cuneiform tablets. The methods section discusses earlier work, including scans of Old Assyrian contracts from the Böhl collection in Leiden. ENCI addresses the practical problem of taking suitable equipment to collections.

Nor does a scan translate a letter by itself. The paper credits Michel with reading, transliterating, translating and interpreting the Old Assyrian texts. Imaging makes the signs accessible. Historical and linguistic work makes them intelligible.

How to check the letters yourself

I would start with the paper, then search within it for the excavation number rather than the headline. Figures 6, 7 and 8 correspond to the three letters discussed here. Read the translation together with the surrounding explanation and figure caption.

Next, open the matching University of Hamburg dataset. Each record identifies the object and lists photographs, reconstructed volume data and geometry files. These are research materials, not a promise that every file will open in a normal browser. The paper says unprocessed tomographic raw data are available from the authors on reasonable request.

Keep the envelope's text separate from the hidden tablet's text in your notes. For Anna-anna, the outside identifies the people. The inside records her attempts to collect silver. Both belong in an account of what this letter tells us.

Sources

• Cécile Michel and colleagues, Deciphering 4000-year-old cuneiform letters hidden in clay envelopes using a mobile X-ray computed tomography scanner, npj Heritage Science 14, article 303 (2026).
• University of Hamburg, First Research Article on ENCI Published, 26 May 2026.
• University of Hamburg research datasets: Kt 94/k 1150, Kt 94/k 602, and Kt 93/k 144, published 18 June 2025.