Can thousands of churches across the world all be telling the truth when they claim to hold a piece of the True Cross? By the late Middle Ages, so many relics were in circulation that skeptics joked they could build a ship—or even a forest—out of them. Yet some devout researchers insist the numbers still add up.
By Lorris Chevalier
The widespread distribution of True Cross relics, along with the tenuous chain of transmission, inevitably led to numerous controversies. By the late Middle Ages, the number of churches claiming to possess a fragment of the True Cross was so vast—both in the East and the West—that doubt became commonplace, especially as popular belief in relics began to wane. Paulinus of Nola had already noted in the early 5th century that the volume of the Cross did not diminish despite the continuous distribution of fragments to visitors.
A Ship or a Forest of Wood?
Reliquary of the True Cross at the Church of the Holy Sepulchre, Jerusalem – Wikimedia Commons
John Calvin, in his Treatise on Relics, claimed that the total sum of the fragments could easily fill a ship. A famous adage goes further, stating that “all the venerated pieces of the True Cross amount to a great forest” or even that they “could have heated Rome for a year.”
Charles Rohault de Fleury (1801-75), a fervent advocate for the sanctity of relics, conducted an inventory of all known fragments of the Cross worldwide, as well as other Passion relics. His findings were far from supporting the idea of an immense quantity, as he calculated that all the fragments he could verify amounted to less than a tenth of the volume of the original True Cross. He wrote:
“I have attempted to document every known relic, whether still in existence or remembered in historical records. I have calculated their volumes in cubic millimetres, basing my calculations on descriptions of relics housed in church treasuries or mentioned in historical texts. Yet, all I have gathered is far from equalling even a tenth of the True Cross’s estimated original volume. The missing nine-tenths must have formed countless unknown or now-lost relics.”
The Distribution of the True Cross
Reliquary if the True Cross at the Museo Diocesano in Genoa – Wikimedia Commons
A pair of early twelfth-century letters offers insights into this debate. Anseau, cantor of the Church of the Holy Sepulchre in Jerusalem, sent fragments of the relics of the Cross to France to be housed at Notre-Dame de Paris. In these letters, Anseau provides details on the fate of the True Cross.
He recounts that in the seventh century, a portion of the Church of the Holy Sepulchre was set ablaze by non-Christians. To save the Cross, the Christians decided to divide it into 19 pieces, which were then distributed as follows:
Constantinople: 3
Cyprus: 2
Crete: 1
Antioch: 3
Edessa: 1
Alexandria: 1
Ascalon: 1
Damascus: 1
Jerusalem: 4
Georgia: 2
The exact dimensions of these relics remain uncertain. Anseau only provides measurements for one of the four relics kept in Jerusalem’s Church of the Holy Sepulchre.
The Final Count
A relic of the True Cross being carried in procession through the Piazza San Marco, Venice, by Gentile Bellini in the 15th century.
Based on available records, the total volume of known relics—including those possibly lost, such as those from Amiens, Donauwörth, Schiras, Grammont, and Jaucourt—amounts to approximately 5 million cubic millimetres. Given the likelihood of many tiny, undocumented fragments in churches, monasteries, and private collections, an estimate tripling this known volume would bring the total to 15 million cubic millimetres. Even this figure falls far short of the estimated 180 million cubic millimetres required to constitute the full volume of the original Cross—a volume roughly equivalent to that of a small tree trunk over two metres tall.
So, while the idea that all the relics of the True Cross could form an entire forest may be a rhetorical flourish—popular among reformers and sceptics alike—the underlying question of authenticity has never been fully resolved. As early as the Middle Ages, observers were aware of the difficulties posed by the sheer number of relics in circulation. Bede the Venerable, John Cantacuzenus, and William Durand all acknowledged the existence of multiple types of wood attributed to the Cross, pointing to an early awareness that the material reality of these relics could not always bear the weight of their claims.
This multiplicity was not always a matter of fraud. In many cases, the provenance of relics was obscured by centuries of war, pilgrimage, and pious substitution. Yet the ambiguity served institutional purposes: relics of the True Cross were potent tools for reinforcing ecclesiastical prestige, attracting pilgrims, and asserting a church’s place in the Christian world. The physical integrity of the Cross mattered less than the authority it conferred.
Whether composed of oak, pine, cedar, or something else entirely, the relics of the True Cross became less a preserved historical artefact than a sacred idea—fragmented, replicated, and venerated across Christendom. They reflect not only the devotional culture of the Middle Ages, but also the ways in which belief could persist—even flourish—amid uncertainty. In this sense, the Cross became more than the sum of its fragments: a symbol of faith, yes, but also of the institutional power and imaginative devotion that shaped medieval Christianity.
Dr Lorris Chevalier, who has a Ph.D. in medieval literature, is a historical advisor for movies, including The Last Duel and Napoleon. Click here to view his website.
Can thousands of churches across the world all be telling the truth when they claim to hold a piece of the True Cross? By the late Middle Ages, so many relics were in circulation that skeptics joked they could build a ship—or even a forest—out of them. Yet some devout researchers insist the numbers still add up.
By Lorris Chevalier
The widespread distribution of True Cross relics, along with the tenuous chain of transmission, inevitably led to numerous controversies. By the late Middle Ages, the number of churches claiming to possess a fragment of the True Cross was so vast—both in the East and the West—that doubt became commonplace, especially as popular belief in relics began to wane. Paulinus of Nola had already noted in the early 5th century that the volume of the Cross did not diminish despite the continuous distribution of fragments to visitors.
A Ship or a Forest of Wood?
John Calvin, in his Treatise on Relics, claimed that the total sum of the fragments could easily fill a ship. A famous adage goes further, stating that “all the venerated pieces of the True Cross amount to a great forest” or even that they “could have heated Rome for a year.”
Charles Rohault de Fleury (1801-75), a fervent advocate for the sanctity of relics, conducted an inventory of all known fragments of the Cross worldwide, as well as other Passion relics. His findings were far from supporting the idea of an immense quantity, as he calculated that all the fragments he could verify amounted to less than a tenth of the volume of the original True Cross. He wrote:
“I have attempted to document every known relic, whether still in existence or remembered in historical records. I have calculated their volumes in cubic millimetres, basing my calculations on descriptions of relics housed in church treasuries or mentioned in historical texts. Yet, all I have gathered is far from equalling even a tenth of the True Cross’s estimated original volume. The missing nine-tenths must have formed countless unknown or now-lost relics.”
The Distribution of the True Cross
A pair of early twelfth-century letters offers insights into this debate. Anseau, cantor of the Church of the Holy Sepulchre in Jerusalem, sent fragments of the relics of the Cross to France to be housed at Notre-Dame de Paris. In these letters, Anseau provides details on the fate of the True Cross.
He recounts that in the seventh century, a portion of the Church of the Holy Sepulchre was set ablaze by non-Christians. To save the Cross, the Christians decided to divide it into 19 pieces, which were then distributed as follows:
The exact dimensions of these relics remain uncertain. Anseau only provides measurements for one of the four relics kept in Jerusalem’s Church of the Holy Sepulchre.
The Final Count
Based on available records, the total volume of known relics—including those possibly lost, such as those from Amiens, Donauwörth, Schiras, Grammont, and Jaucourt—amounts to approximately 5 million cubic millimetres. Given the likelihood of many tiny, undocumented fragments in churches, monasteries, and private collections, an estimate tripling this known volume would bring the total to 15 million cubic millimetres. Even this figure falls far short of the estimated 180 million cubic millimetres required to constitute the full volume of the original Cross—a volume roughly equivalent to that of a small tree trunk over two metres tall.
So, while the idea that all the relics of the True Cross could form an entire forest may be a rhetorical flourish—popular among reformers and sceptics alike—the underlying question of authenticity has never been fully resolved. As early as the Middle Ages, observers were aware of the difficulties posed by the sheer number of relics in circulation. Bede the Venerable, John Cantacuzenus, and William Durand all acknowledged the existence of multiple types of wood attributed to the Cross, pointing to an early awareness that the material reality of these relics could not always bear the weight of their claims.
This multiplicity was not always a matter of fraud. In many cases, the provenance of relics was obscured by centuries of war, pilgrimage, and pious substitution. Yet the ambiguity served institutional purposes: relics of the True Cross were potent tools for reinforcing ecclesiastical prestige, attracting pilgrims, and asserting a church’s place in the Christian world. The physical integrity of the Cross mattered less than the authority it conferred.
Whether composed of oak, pine, cedar, or something else entirely, the relics of the True Cross became less a preserved historical artefact than a sacred idea—fragmented, replicated, and venerated across Christendom. They reflect not only the devotional culture of the Middle Ages, but also the ways in which belief could persist—even flourish—amid uncertainty. In this sense, the Cross became more than the sum of its fragments: a symbol of faith, yes, but also of the institutional power and imaginative devotion that shaped medieval Christianity.
Dr Lorris Chevalier, who has a Ph.D. in medieval literature, is a historical advisor for movies, including The Last Duel and Napoleon. Click here to view his website.
Click here to read more from Lorris Chevalier
Further Readings:
Charles Rohault de Fleury, Mémoire sur les instruments de la passion de N.-S. J.-C., L. Lesort, 1870
Geneviève Bautier, “L’envoi de la relique de la Vraie Croix à Notre-Dame de Paris en 1120,” Bibliothèque de l’École des chartes, Vol. 129:2 (1971)
Top Image: Getty MS Ludwig IX 13 – Gualenghi-d’Este Hours
Subscribe to Medievalverse
Related Posts