E. Monroe: The Madara Horseman located in northeast Bulgaria is listed as a UNESCO World Heritage Site. It is a rock relief carved into a vertical cliff face depicting a life-size horseman, a lion, a dog and inscriptions. Can you describe the relief in more detail?
V. Todorov: In the relief scene, a man on horseback sits in the posture of a king, one who has won a magnificent victory. He is stabbing a lion with a spear that lies in agony below the hooves of the horse. A dog is in mid-pace, running after the horse. There are also three sets of writings in the Greek language, two below the horse and one to the front. The relief is entirely unique; no similar work has been created in Europe before or since its construction.
E. Monroe: In the past, the monument was thought to be the work of Roman or even Thracian sculptures. More recently it has been dated to the early Middle Ages. How has the age of the stone relief been determined?
V. Todorov: There has been much speculation in the past, but today we know exactly when the relief was created. Before World War 2, the common belief was that the horseman was Khan Krum who ruled Bulgaria from 804 – 815 AD. In fact, a Bulgarian coin was minted in the 1930’s with a picture of the relief credited to Khan Krum. Many investigations later, a leading Bulgarian archaeologist, Vesilin Besheliev, determined the age of the relief at 705 AD just 24 years after the founding of Bulgaria in 681 AD. The age is founded on the inscriptions, one of which describes the relationship of the Bulgarian Khan Tervil with Justinian II, Emperor of the Eastern Roman Empire. The inscription notes Justinian II’s acceptance of Khan Tervil’s rule over Bulgaria with the gesture of bestowing gifts. It was during the rule of Khan Tervil that, in fact, the Byzantines paid tax to the Bulgarians.
E. Monroe: The relief was cut 23m above the base of a vertical rock face. In all, the rock face is 100 meters in height. There are holes cut into the stone below the relief. Were these holes cut to support wooden beams for scaffolding?
V. Todorov: Yes, these holes were used exactly for that.
E. Monroe: The stone that makes up the cliff face is known as limy sandstone, a sedimentary rock. It has a characteristic layering appearance and is relatively soft. What tools would early sculptures use to carve into the rock face?
V. Todorov: This is a very good question, but one that cannot be answered. Weathering and erosion has destroyed any tool marks that would have existed on the rock face. Monuments that have been protected from weathering are more likely to show such marks. For example, even though it is older, at the Thracian tomb in Sveshtari, you can actually see how they cut the stone by observing the surface. While there is no such evidence at the Madara site, it is interesting to note traces of red painted plaster found in different parts of the relief. Measuring 2mm in thickness in places, the plaster was likely used to highlight the relief.
E. Monroe: The Madara Horseman rock face is part of the western vertical slope of the Madara Plateau. Tectonic processes like earthquakes were involved in the formation of the rock face and are currently involved in its destruction, including the relief. A large fracture is visible through the later half of the horse. What can be done to slow this natural process?
V. Todorov: For 1 300 years the relief has stayed in place, but we should prepare it for many more. We are monitoring its movement. It is slipping very slowly due to fractures in the rock on either side of the horse. One project proposal for stabilising the relief is to anchor it to the cliff face, but this approach has not been decided upon.
E. Monroe: I understand that the biologic degrading of the rock surface is also a concern and your specific area of study. Can you tell me more about your research?
V. Todorov: The reason the relief has survived so long is due to a natural hardening of the stone. This happens through what is called a karstic process. When carbon dioxide from the air combines with rainwater, a weak carbonic acid is formed. Carbonic acid is the acid that breaks down limestone to form caves. In the case of the Madara Horseman, the acid produces bicarbonate that is soluble in water and carried over the face of the relief when it rains. As the water evaporates, a new layer of calcium carbonate hardens over the surface and protects it from weathering.
Unfortunately, lichens living on the surface are damaging the relief. Lichens are known as pioneer micro-organisms, algae and fungi that are capable of breaking down rock material. Their roots will penetrate cracks in the rock and produce an organic acid that dissolves calcium carbonate. The presence of lichen on the rock surface is visible in a slightly greyer appearance. The unaffected rock of the relief will have a yellowish shade. Lichens require sunlight, water, and nutrients in the form of airborne particles. This is why parts of the cliff that are tilted slightly upwards provide a more suitable environment for the lichens to grow. The detail of the relief in such places is poor.
E. Monroe: Do you have any preliminary ideas as to how the relief could be treated?
V. Todorov: Yes, the relief can be shielded from rainwater and airborne particles with a roof mounted to the rock face. In that position it will be only partially visible to visitors and effectively inhibit the growth of lichens. The roof will also be constructed with brass which when exposed to weather, leaches copper ions. The leached cooper acts as a natural biocide against the lichen populations.
Currently, I am testing these theories at the Madara site with two other professors- Dr. Warshneid from Aldenberg, Germany and Dr. Orial from the French Laboratory on Historic Monuments. We are installing an experimental roof on the same rock face, but some distance away from the actual relief. In addition, we will experiment with artificial calcification of the rock surface to imitate natural preservation processes. To date, we have funding only for the initial stage of these investigations. We are looking for additional support.
E Monroe: The area around the Madara Horseman contains remnants from the times of primitive man, as well as monk chambers dating to the late Middle Ages. What more can you tell about this area?
V. Todorov: The area of the Madara Horseman is a historical and archaeological reserve. Monuments from six different historical periods can be found there, including: prehistoric caves, Roman settlements, monuments from protobulgarians, medieval Christian churches, and rocky chambers of monks following the Ottoman invasion. Indeed, this is a sacred place known by many people around the world.
Dr. Valentin Todorov is a conservation scientist with the Department of Conservation and Restoration at the National Academy of Arts. As a member of the National Council of Monuments of Culture, he has over thirty years of experience in conservation of historical monuments and buildings.
Edward Monroe is conducting research in Bulgaria through a Fulbright Fellowship. His research project is entitled, “Building Stones of Bulgaria from Ancient Times to the Present”. The purpose is to create educational materials about Bulgaria’s unique historical stone monuments and buildings.
