The Shroud of Turin: A Cloth That Will Not Settle

On the evening of 28 May 1898, an amateur photographer named Secondo Pia developed a glass plate in his darkroom in Turin. He had just been allowed to photograph a long, yellowed strip of linen displayed above the cathedral altar. On it was the faint, straw-coloured image of a man, front and back, laid head to head. When the negative emerged in the developing bath, Pia saw something he had not expected. The dark-and-light values of the cloth's image were reversed on the plate, and the reversal looked like a more natural face, the way an ordinary photograph looks. The image on the cloth, in other words, behaves like a negative. That discovery, made more than five centuries after the cloth's first documented appearance, turned a medieval relic into a modern scientific problem, and it has not been settled since.

This entry sets out what the cloth physically is, what its documented history is, what every major test has found, and where the evidence genuinely points. It keeps faith in the cloth, the laboratory results and the unresolved puzzles as three separate things.

The object

The Shroud is a single piece of linen, about 4.4 metres long and 1.1 metres wide, woven in a 3-over-1 herringbone twill, a relatively elaborate weave. A narrow strip runs along one long edge, joined by a seam. On the cloth are:

• a faint body image, frontal and dorsal, of a bearded man with his hands crossed. The image is extremely superficial, affecting only the top fibres of the threads;
• reddish stains in the places associated with the wounds of crucifixion: wrists, feet, side, scalp and back;
• two long lines of scorch marks and holes from a fire in 1532, when the folded cloth was damaged inside its silver reliquary;
• water stains from the same fire;
• until 2002, about thirty patches sewn on by the Poor Clare nuns of Chambéry in 1534, together with a backing cloth. Sources count them slightly differently.

A documented history, and a long silence before it

• c. 1354–1355, Lirey (France). The cloth first appears in the historical record in the collegiate church founded by the knight Geoffroi de Charny. A lead pilgrim's badge found in Paris (now in the Musée de Cluny) shows a long cloth with a double body image and the arms of the Charny and Vergy families. It is physical evidence that the cloth was being shown to pilgrims. How Charny came to own it is not recorded.
• 1389. Pierre d'Arcis, bishop of Troyes, wrote a memorandum to the Avignon pope Clement VII. He said that an earlier bishop had investigated the cloth and that an artist had confessed to painting it. Clement allowed the showings to continue on the condition that it be announced as a "figure or representation" and not as the true shroud. The memorandum is a real document. Whether its claim is accurate is contested, because no artist is named and the investigation's records do not survive.
• 1453. Margaret de Charny passed the cloth to Duke Louis I of Savoy. It became a dynastic treasure of the House of Savoy.
• 1532–1534. Fire at Chambéry; the Poor Clare nuns carried out the repairs.
• 1578. Moved to Turin, the new Savoy capital.
• 1898. Secondo Pia's photographs.
• 1978. The Shroud of Turin Research Project (STURP), a team of mostly American scientists, examined the cloth directly for five days.
• 1983. The former king Umberto II left the cloth to the pope on condition that it remain in Turin.
• 1988. Samples were taken for radiocarbon dating (see below).
• 1997. A fire in the Guarini Chapel. The cloth, in its case, was carried out of the cathedral.
• 2002. A conservation campaign removed the 1534 patches and backing and photographed the reverse of the cloth for the first time. Some specialists criticised the intervention.

Before 1354 there is no document that unambiguously refers to this cloth. Several hypotheses try to bridge the gap. The best known, argued by Ian Wilson, identifies it with the Image of Edessa (the Mandylion), a cloth bearing Christ's face venerated at Constantinople. Other arguments point to a twelfth-century Hungarian manuscript, the Pray Codex, whose drawing of Christ's burial some read as showing features of the Shroud. These links are argued, not demonstrated. Historians who reject them point out that the Mandylion was described as showing a face only, and that the Pray Codex drawing can be read in other ways.

The 1988 radiocarbon dating

On 21 April 1988 a strip was cut from one corner of the cloth and divided among three laboratories: the University of Arizona, the University of Oxford and the ETH in Zurich. The British Museum coordinated the work. The combined result, published in Nature in 1989 (Damon et al.), placed the linen between 1260 and 1390 CE with 95% confidence. That is consistent with the cloth's first appearance at Lirey in the 1350s.

The result has faced three kinds of challenge, and each has had a response:

• The sample was unrepresentative. The chemist Raymond Rogers, a STURP member, argued in Thermochimica Acta (2005) that the sampled corner contained medieval repair threads with cotton and a dye coating, so the date would reflect a repair. Against: a 2010 examination of remaining Arizona material by Freer-Waters and Jull in the journal Radiocarbon reported no evidence of reweaving or dye coating in what they examined. Still disputed.
• The statistics were flawed. In 2019, Casabianca and colleagues in Archaeometry analysed the raw data, released only in 2017 after a legal request. They reported heterogeneity between the laboratories and a trend across the sample, and argued that the result should be re-examined. Against: heterogeneity does not by itself move the date to the first century, and the authors did not claim that it did.
• Other dating methods disagree. In 2022, Liberato De Caro and colleagues reported a wide-angle X-ray scattering (WAXS) test on a single thread. They argued that its cellulose ageing matched first-century linen. Against: the method is new and not independently replicated, depends on assumptions about storage temperature and humidity over the centuries, and rests on a tiny sample. Earlier alternative dating methods from the same research circle drew similar criticism.

The consensus position among radiocarbon specialists is that the 1988 dating is sound. A substantial minority of researchers, many of them sindonologists (specialists in the Shroud), argue that it is not. This entry records both positions and does not claim to settle the question.

The image and the "blood"

What STURP found (1978–1981). STURP concluded that the body image was not made by paint, pigment or dye. The colour sits in the topmost fibrils of the linen as a degradation (dehydration and oxidation) of the cellulose. STURP members John Heller and Alan Adler reported that the reddish stains gave chemical results consistent with blood. Walter McCrone, a microscopist who examined STURP's sticky-tape samples, disagreed: he reported iron oxide and vermilion pigments and concluded that the image was painted. Heller and Adler replied that pigment particles were present but too sparse to form the image, and that such particles could have been transferred from painted copies pressed to the cloth over the centuries. The disagreement was never resolved to both sides' satisfaction.

How the image was made remains unexplained. No one has a demonstrated mechanism that reproduces all of its measured properties at once: superficiality, negative-like values, the absence of brush marks, and the way the image corresponds to distance from a body. Hypotheses range from medieval techniques to exotic radiation. None is established. The chemist Luigi Garlaschelli produced a full-size reproduction in 2009 using materials available in the Middle Ages. He argued that it matched many properties. Critics argued that it did not match the superficiality and other features.

Bloodstain patterns. In 2018, Matteo Borrini and Luigi Garlaschelli used bloodstain-pattern analysis in the Journal of Forensic Sciences. They reported that the blood flows on the forearms and the side could not be reproduced by any single body position of a crucified or buried man, and they read this as evidence of an artificial origin. The study was criticised for its methods, including its simplified experiments on a living volunteer.

The "three-dimensional" claim. In 1976 researchers fed a photograph of the Shroud into a VP-8 Image Analyzer and obtained a coherent relief of the figure. This is often cited as proof that the image encodes distance from a body. Critics note that any image with smooth brightness gradients can produce such a relief, and that some paintings do too. The observation is real. What it means is disputed.

Claims that are not supported. These are repeated often but fail on the evidence:

• Pollen from Palestine (Max Frei). His samples and methods have not stood up to later scrutiny.
• Coins over the eyes. These are pattern-readings of the weave.
• Hidden writing on the cloth. These are interpretations of noise in enhanced photographs.

Symbology and sacred meaning

The negative as revelation. Pia's reversed plate became the source of the devotion to the Holy Face. The "positive" face from the photographic negative circulates as a devotional image. The devotional meaning is real. It is a separate matter from the cloth's date.

Icon, not relic. The Catholic Church has never officially declared the Shroud authentic. Recent popes, including Benedict XVI and Francis, have spoken of it as an icon of Christ's passion and of "the Man of the Shroud", and they encourage its veneration whatever its origin. The distinction between an icon, an image that leads to prayer, and a relic, a physical remnant of a holy person, is exactly the line this archive draws between belief and evidence.

Dynastic palladium. For the House of Savoy the Shroud was a protective treasure of the dynasty. It was carried with the court, displayed at weddings and moved to the new capital at Turin. Its politics are as documented as its piety.

The wounds as text. Devotional and medical readers treat the stains as a narrative of the Passion written in the cloth: scourge marks, a cap of thorns, a lance wound, nail wounds in the wrists rather than the palms. Many see the wrist placement as a detail a medieval painter would not have chosen. Others note that medieval art varied and that the "wound" areas can be read in more than one way. The observation is contested in both directions.

Connections

The Shroud belongs with the archive's chapters on patristic and Byzantine Christianity (ch22, ch60), where the cult of relics and of images "not made by hands" such as the Mandylion developed, and with the Reformation (ch31), whose critics attacked the relic trade. Its fellow objects in the Vault are the Holy Lance (V05) and the Crown of Thorns (V06): the other "instruments of the Passion" whose cults the same courts and cathedrals promoted.

From The Divine Archives · https://getconexto.com/vault/shroud-of-turin.html