The secrets of church walls

All things ferrous

One of the great myths surrounding the story of medieval Gothic architecture is the claim that the clever masons of the Middle Ages found a new way of constructing impressively tall churches and cathedrals with large expanses of tracery and stained glass by using pointed arches and vaults that become stronger the more they are compressed, along with massive buttresses to carry the weight of the stonework to the ground. Anyone who has been privileged to visit the hidden parts of a medieval cathedral will confirm that this is not the whole story: large quantities of ironwork were also employed to hold the building together.

Conservation work at the Notre-Dame cathedral in Paris has revealed that it was perhaps the earliest Gothic cathedral to use iron on a large scale in its construction. IMAGE: Wikimedia Commons, Ali Sabbagh

The masons’ skill was to hide the ferramenta, as it is known, underneath floorboards and in the space above the vaults to give the appearance that the stonework is self-supporting. In particular, the adjacent blocks of stone that make up the walls of the cathedral have holes and channels carved into the surface to accommodate massive iron staples that are secured with molten lead – literally stitching the blocks of stone together. Iron tie-rods located above the aisle, nave, and sanctuary vaults help to keep the walls from leaning outwards and spreading. The stonework of the nave and sanctuary arcade columns is also full of iron pins to prevent the component blocks from sliding apart and collapsing.

On a medieval building site, iron-working was thus as integral a part of the building process as stoneworking. The failure to recognise this has led to some near disasters: the belief that the use of iron armatures was a feature of 19th-century restoration led to the tie- rods at Beauvais cathedral being removed, leading to major structural issues.

The ‘first Iron Lady’

Perhaps more people are now aware of the early and widespread use of iron thanks to the conservation work taking place to restore Notre-Dame cathedral in Paris, following the destructive inferno that engulfed the building in 2019. Archaeologists have been studying what they have described as the ‘iron skeleton’ of the building and have claimed that the use of iron to build Notre-Dame was ‘groundbreaking’ and that the cathedral was the first building of its kind to be constructed in this way.

In a paper published in the online journal PLOS ONE (, the authors describe the cathedral as ‘the first Iron Lady’, and go on to say that the restoration of the monument after the fire offered a unique opportunity to sample 12 of the iron staples that were used to bind and stabilise the building’s stonework – each measuring from 25cm to 50cm in length and weighing from 2.5kg to 4kg. Six of them, taken from different locations (the tribunes, nave aisles, and upper walls), were dated to the mid-12th century: in other words, to the earliest phases of Notre-Dame’s construction, which began in the 1160s.

On the basis of that early date, the authors claim that Notre-Dame was the first Gothic cathedral where iron was used on a large scale as an integral constructional material. Perhaps this early use of metal suggested that the masons were in two minds about the potential stability of such a large building based purely on the load-bearing capacity of arches, vaults, and buttresses – it must always have been an anxious moment for cathedral-builders when the formwork was removed to see whether their constructions held up. Even if it was just a precautionary measure, the use of iron was rapidly and widely adopted: the same techniques were subsequently deployed to construct the increasingly tall nave vaults of the magnificent cathedrals at Chartres, Bourges, Reims, Amiens, and Beauvais.

A large part of the PLOS ONE paper is devoted to an analysis of the chemical structure of the iron staples and the details of their production by welding smaller iron ingots together. This reveals that the cathedral obtained its metal from at least six different ironworks, and the article concludes with a call for further ferramenta studies to throw light on the market for iron in Europe in the 12th and 13th centuries, and to understand the scale of the industry and how such large quantities were produced and circulated.

Graffiti is no new phenomenon

Graffiti is another ubiquitous feature of historic places of worship that has often been overlooked in the past – or perhaps dismissed as vandalism – but that is now the subject of serious study. In the UK, Matthew Champion set up the Norfolk and Suffolk Medieval Graffiti Surveys ( as volunteer-led projects to record the surviving historical inscriptions in those two counties, resulting in tens of thousands of new records. His book on Medieval Graffiti (2015) opened our eyes to the rich legacy of charms, witch-marks, pentangles, and compass-drawn daisy wheels to be found around doorways and on nave arcades, inspiring other county-based archaeology and history societies to embark on similar systematic surveys.

Medieval graffiti, like this apotropaic mark carved into the wall of a church in Worlington, Suffolk, has been found in many places of worship. IMAGE: Wikimedia Commons, Medievalg

As a result, we now have a large body of information about the graffiti inscribed into church masonry, roofing lead, and the woodwork of pews and choir stalls. The repertoire includes depictions of full-rigged sailing ships, designs for tracery windows, musical notation, knights and dragons in combat, birds and fish, mass dials, and memorial inscriptions. Indeed, had King Charles been in need of distraction or amusement during his Coronation in May 2023, he could have done worse than study all the graffiti carved into the woodwork of the Coronation Chair, constructed in 1297 for King Edward I and now marked by the initials and (mainly 18th-century) dates of tourists and abbey choirboys.

Cypriot graffiti

Medieval graffiti is not restricted to the British Isles, however. Mia Gaia Trentin of STARC (the Science and Technology in Archaeology and Culture Research Center) at the Cyprus Institute is leading a project to study Cypriot graffiti, which is especially significant because of the island’s geographical position at the crossroads between the Mediterranean’s western and eastern sea lanes. It was the last stop for ships going to Syria, Lebanon, and Egypt, and the first on their way back.

Quite a number of Cypriot graffiti depict ships – thanksgiving, perhaps, for safe passage. Names or initials are common, sometimes with a date. Numerous 18th- and 19th-century visitors to Bellapais Abbey left their names and dates of their visits. Some of them have been identified as members of wealthy families from Larnaca who visited the abbey during holidays at their summer residences in the hills around Kyrenia.

The locations of the graffiti can be significant. On the whole, tourists respected the more sacred areas of a church and left their marks on door jambs, though some also found the softer alabaster of effigial monuments irresistible. That the clergy were not averse to leaving their mark is testified by names, dates, and sometimes titles in the sanctuary to which, in theory at least, the laity had no access. Thus graffiti (in Greek script) records the visits of the priest/monk Teratziotis-Avgorou to Agios Georgios and the deacon Stegis-Kakopetria to Agios Nikolaos. Heraldry enables the Holy Land itineraries of pilgrims and Grand Tourists to be traced, and various personal marks or monograms are testament to the frequency with which Venetian merchants visited Cypriot churches.

Pledges and protection

Where the graffiti occurs within the body of the church – and specifically, in Cyprus, scratched into wall plaster, carved into the iconostasis, or close to the relics of a saint – it is likely that an oath, vow, or pledge is involved, made more sacred and unbreakable by being made in the sight of God or witnessed by saints. A graffito of this kind also functioned as an unofficial memorial to a deceased friend or relative – for example, the Greek inscription in Agia Paraskevi Geroskipou church that stated: ‘God’s servant Georgios died the 31st of October’.

Sometimes it is a challenge to understand the messages and ideas that graffiti are intended to convey, but many are apotropaic – that splendid term derived from the Greek word to avert evil. These graffiti often take the form of complex geometric patterns designed to trap the easily confused agents of misfortune. Also common are double-V shapes, standing for Virgo Virginum (‘Virgin of Virgins’), which also form an ‘M’ for Maria when inverted. In Cyprus, this type of graffiti occurs in the doors, windows, and fireplaces of secular buildings as well as places of worship, showing that there was a pan-European language of symbols, shapes, and motifs in the Middle Ages.