The symbology of the Rotunda of Saint Thomas

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A pretty tree-lined avenue leads to the Rotunda of Saint Thomas. The ground is covered with fallen orange and brown leaves. Although the autumn advances with an atmosphere of transience, the centuries-old trees on either side of the short walkway seem not care. The graceful place gives a lot of tranquillity and inspires inner peace. Under a sunny sky, the Romanesque Rotunda of Saint Thomas appears. The silence of the avenue was only interrupted by the noise of our footsteps.

The Rotunda of Saint Thomas

Here is a rare circular Romanesque church. The building is similar to other constructions in Lombardy: the Duomo Vecchio in Brescia and the Rotunda of San Lorenzo in Mantova.

The Rotunda of Saint Thomas has a plan with three concentric cylindrical volumes and sloping roofs. This architectural feat enhances the great monumentality of the structure. Externally, the Rotunda is surrounded by sixteen lesenes; a drum with a lantern constitutes the upper concentric plane.

The pink limestone rock of the Rotunda is connected to the surrounding countryside creating an imaginary continuation of the material. The building opens through two splayed portals with round arches. Moreover, the main portal is decorated with reliefs, including human figures, on the sides of the architrave. The sculpted lunette of the side portal is stunning. Here the symbols of a knot, a tree and a human figure are carved. The side portal is known as the convent door because in ancient times it led to a small women’s monastery.

Light comes from the single and mullioned windows, creating a mystical atmosphere inside the Rotunda. A nice eight-column cross-vaulted ambulatory encloses the magnificent matroneum. Remains of some frescoes are visible on the walls of the women’s gallery. The original capitals are sculpted with geometrical symbols and scenes from the biblical Book of Tobias. Further, the extraordinary decorations were probably carried out by expert stonemasons, such as the Comacine Masters. The main altar is located in the apse chapel.

The Rotunda of Saint Thomas over time and over space

The Rotunda is located near Bergamo, far from the noise and confusion of the city; Almenno San Bartolomeo is its nearest city center. It is a sacred place since ancient times. Once there was the pre-Roman city of Lemine, near the banks of the Brembo river. Nonetheless, despite the millennial history of these places, we have little information about the Rotunda’s origin. It seems to be wrapped in an undecipherable darkness.

A debated origin

The origin of the Rotunda of Saint Thomas is still debated. According to a popular tradition spread in Lombardy, the Rotunda of Saint Thomas was built on an old Roman temple. However, archaeological investigations have confirmed this is a myth1. Indeed, a basement from the Classical period has not found by the archaeologists. The monument could be from the Lombard period, or Carolingian one, which the ambulatory’s columns could belong to. They rest on a kind of inverted capitals with the purpose of increasing the height.

Probably the Bishop of Bergamo ordered to construct the Romanesque Rotunda of Saint Thomas over this pre-existing Carolingian edifice. In any case the first official document attesting the existence of the building is a testament from the second half of the12th century. The Ecclesiae Sanctae Tomei is mentioned in a bequest of a man, called Girardo Moizoni and shows that the Rotunda already existed in 1160-1180.

Another document refers to the location of the building, in Latin, that it was in territorio burgi de lemine ubi dicitur ad pontem S.ti Thomei. It is the Rotulum decimarum2, an inventory on the properties of the Lemine church dating to 1353.

The sacred geometry of the Rotunda of Saint Thomas

A complex symbology gives a mysterious charm to the Rotunda of Saint Thomas. It mainly concerns the sacred geometry of the building. In fact, it is not so common to see a church with a circular plan like the Rotunda. This has a precise meaning. In the Middle Ages, the circle was symbol of the whole, cosmos and the entire creation. Hence, it is not surprising that the church of Saint Thomas could be considered as a temple where God’s work is celebrated. The number of the columns in the ambulatory on the ground floor and in the women’s gallery confirms this idea. Here are several elements referring to the Christian numerology of the eight, which indicates the seven days of the Creation and the day of the eternal life.

All these characteristics seem to be related to the Holy Sepulcher in Jerusalem, of which the Rotunda of Saint Thomas could be a reproduction. Even the light, which creates a mystical effect inside the monument, ideally leads the visitor to Jerusalem where Christ was buried. On the summer solstice, the 20th June 1997, the building’s guardian observed a strange phenomenon. The sun’s rays penetrated through the small window of the facade and illuminated the tabernacle of the main altar. Since that day several studies have been conducted on the astronomical significance of the Rotunda of Saint Thomas. The research proposed by Adriano Gaspani of the Astronomical Observatory of Brera is of particular interest3.

Symbology of the Rotunda of Saint Thomas

There are many similarities between the Rotunda of Saint Thomas and the city of Jerusalem, such as the sacred geometry and symbology. At the Door of the convent the lunette shows three sculpted figures: the representation of a man, probably with a spear, a Solomon’s Knot and a palm tree. These symbols are similar to that used by the hierosolimitan orders in the Holy Land. So, the Solomon’s Knot symbolizes the indissoluble relationship between God and man. The palm tree, in a wider meaning of the tree of life, is also connected to the city of Jerusalem and to the story of Christ.

The Archangel Raphael

For a better understanding of the symbols on the door of the convent lunette they need to be read as a whole. A hypothesis based on the studies by Ernst Gombrich suggests that the man depicted at the lunette could be the Archangel Raphael; the capitals of the ambulatory illustrate stories from the Book of Tobias. Tobias was helped by Archangel Raphael in curing his father’s blindness and casting out demons.

Another clue focuses on the apotropaic and worship function that Raphael had in the Middle Ages. He was the angel associated with healing and exorcism. Moreover, Raphael was the protector of wayfarers and pilgrims. Hence, his carved representation had the function of casting out the evil from the church and convent. Here, the evil is considered in both its spiritual and physical meaning.

The Rotunda of Saint Thomas and the Knights Templar: a possible connection

It was hypothesized that the Rotunda of St. Thomas was linked to a hierosolimitan order that managed a hospital (spitale) for pilgrims, whom prayed to the archangel for healing. In addition, a wall was discovered around the Rotunda, which possibly enclosed a cemetery4.

Which monastic order had a hospital and a cemetery in Almenno San Bartolomeo? Probably they were the Knights Templar, who spread the Solomon’s Knot during the Middle Ages. The Templars were precisely based in the area of the lost Temple in Jerusalem. Furthermore, the presence of the Knights Templar at the Rotunda of Saint Thomas is confirmed by indirect historical sources: the testament of Girardo Moizoni mentions a College of Crusaders and a Domus Templi near it.

Templar clues

The Rotunda of Saint Thomas with its geometry recalls the astronomical and architectural knowledge of the Order of the Temple. Some clues suggest their presence: internally there are seven empty niches which hosted standing prayers, as in monastic rites. Externally a holy water stoup, placed at an unusual height, was used to bless knights on horseback. This is how the Templars received the blessing of the Church for safeguarding pilgrims along the missio.

Samuele Corrente Naso

Map of places


  1. C. R. Nodari, P. Manzoni, La Rotonda di San Tomè. Analisi di un’architettura romanica, 1997. ↩︎
  2. Ibidem ↩︎
  3. A. Gaspani, S. Tomè. Astronomia, geometria e simbolismo cosmico in una chiesa romanica, 2013. ↩︎
  4. P. Piva, Le copie del Santo Sepolcro nell’Occidente romanico: varianti di una relazione problematica, 2000. ↩︎


Samuele avatar

Samuele is the founder of Indagini e Misteri, a blog on anthropology, history and art. He has a degree in forensic biology and works for the Ministry of Culture. For pleasure he studies unusual and ancient things, such as unclear symbols or enigmatic apotropaic rituals. He pursues the mystery through adventure but inexplicably it is is always one step further.

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