REPRINT

THE BUILDING MATERIALS OF THE MONUMENTS OF THE MEDIEVAL CITY OF RHODES AND THE COMPATIBILITY PROBLEMS WITH MAINTENANCE

Elias E. Kollias

The medieval city of Rhodes 1 is the legitimate offspring of the Hellenistic city, so it would probably be best to say that it is the same city which, in 408 BC, the ancient Rhodians founded at the northern most end of their island, different of course and much smaller.

During the Hellenistic years it was one of the most beautiful and organized cities of the world. It was divided by straight roads, according to the hippodamian street-plan system; it was decorated with churches, gymnasiums and other bright public and private building and was protected by mighty fortifications.

During the Early-Christian years, Rhodes continued to be a great and bright city, the center of the Aegean, capital of the province of islands and headquarters of the metropolis of Rhodes with twenty Bishoprics as «subjects», some of which belong to large islands, such as Naxos, Samos, Mytilene and Kos. The Rhodians continue to have the ability to design and the potential to construct great and luxurious buildings, public and private, and to decorate them with frescos, enwalled mosaics and architectural marble pieces, elaborately carved. The city functions as in the Hellenistic years, roughly maintaining the hippodamian street-plan system with only small deviations and the approximately all of its remaining Hellenistic town accouterments. The conditions change in the Aegean from the 7 t h century. The Byzantine empire loses its provinces wealthy in materials and cultural riches, in Syria, Palestine and North Africa. The islands are threatened by the fury of the Arabic fleet which is plowing through the Aegean. The coastal settlements on the islands are destroyed and pillaged by the Arabs. Their residents abandoned them and escaped from their islands or withdraw to safer places which they fortified . Few settlements of the Aegean remain in the locations they held in antiquity. Rhodes is one of them. It is quite likely that during the last quarter of the 7 t h century,

the ancient settlement was not abandoned and that the population, as reported in historic Arabic sources, in times of enemy invasion, took refuge in a fort. The size and the position of this fort are elements which we can define today. It was the place which under the reign of the knights was called Collachium.

Around the end of the 11 t h century or at the beginning of the 12 t h century, the fortification expands and encloses within the walls the section of the settlement which was spreading without fortification to the south of Collachium. Therefore, the city takes a longer parallelogram shape, which was generally in accordance to that of practically all of the Post-Roman and Early-Christian cities of Asia Minor and the Middle East. Under the reign of the knights, with the extensions made during the 14 t h and 15 t h centuries, it changes shape, inclining towards the circular and enclosing the trade harbour, the great port of ancient Rhodes.

During the period of the Turkish empire (1522 - 1912) practically nothing changes in the structure of the medieval city. The broad high street, the «Magna et communis Platea» as it was called during the reign of the knights, becomes narrower with the construction of houses and largely with the construction of shops. Two public baths and six Mosques are constructed and many buildings are later constructed with light materials using wood and plaster, with which covered wooden balconies and dividing walls are made.

The basic material with which the city of Rhodes was built and shaped from the time it was founded in 408 BC until the end of the Turkish empire, was the calcareous sandstone. Sources of derivation of this material for the medieval period were initially the ancient structural relics which encompassed the city. The vita of Saint Fanourios reports that during the years of metropolite Neilos Diasorinos (1357 - 1369), the «master» of Rhodes in other words the Grand master Roger de Pins (1355 - 1365) or Raymond de Berenger (1365 - 1373) decided to «reconstruct the walls of the country» 2 and gave the command to extract structural material from derelict ancient constructions south of the city. During the course of the salvaging excavation and search in the city of Rhodes, very often traces of extraction of structural material from derelict ancient constructions are discovered. In the relics of Byzantine buildings and mainly of the fortifications, but also in structures of the early period of the knights , it is easy to distinguish the use of ancient sandstone, as well as other architectural pieces 3 . Naturally sandstone mining quarries were also used. Until today, the traces of quarry marks in the medieval moat are evident. Wherever the knights found sandstone, while digging and deepening the moa t 4 , they extracted it and used it for the construction of fortifications and buildings. Medieval quarries 5

can also be sighted on the beach of the southeastern region of the city at the location of Karakonero, at the southern region of the city, in the district of Saint Ioannis 6 , and south of the village Koskinou, which lies approximately 6-7 kms away from the city.

In addition, the two sandstone quarries in the city of Rhodes are known only from the historic sources. One lay at the location of Livada on the northern side of today's city and belonged to the priest Emanuel Magkafas 7 , who donated a quantity of sand stone to the knights Battalion under the Grand master A. Fluvian ( 1421 - 1437) for the construction of the walls. The second lay close to the «arches of Arsenal» 8 (Juxta Voltas arsenalis), according to a document of the Hospitaller Archive in Malta. From this quarry, the Prior of the conventual church J. Morel in 1441 who was assigned as supervisor by the Hospitaller Battalion, could extract stone for the construction of the great new hospital. The areas and the two quarries have yet to be located.

The customary construction system of sandstone from the Early-Christian years until the end of the Turkish empire was ashlar.

In the Early-Christian years, and particularly in the early Byzantine and middle Byzantine years, the ancient construction material which was derived from the relics of the Hellenistic city was used without being processed or was processed only enough to slightly improve the method of joining the stone bricks. Most often during construction, they instated pieces of the tiles for the satisfactory placement of the stones. The joints have a width of 0.05 to 0.10 m and usually were enclosed with a lime mortar 9 . The walls however, give the feeling of an ashlar construction. During the Byzantine period, this system is often combined with the webbing system 10, in particular when walls of great width are being constructed , which begin at 0.80 m and in fortifications reach up to 3.00 or 3.20 m. In these cases, two parallel walls were built and the space between them was filled with clay stones and clay, but sometimes the two external walls were also connected with transversely placed stone blocks.

During the reign of the knights, in particular during the first half of the 14th

century, building using construction material derived from the structural remains of the ancient city continued. The Voyagers who visited Rhodes then, admired the size of the stone blocks which the knights used in the construction, largely, of fortifications. They were large stone blocks whose length usually exceeded 1.50 m and had a height of 0.48 to 0.50 m. Later l 2 , and especially from the 15 t h century onwards, the knights used smaller sized stone blocks whose length did not usually exceed 0.30 to 0.35 m and formed tiles from 0.22 to 0.26 m, even though sometimes the height of the tiles on the fortifications reaches 0.40 m, especially at the end of the }5Λ century and at the beginning of the 16 t h century under the grand masters D'Aubusson, D'Amboise and Del Caretto. In this period , the horizontal and vertical joints are straight, and in the fortifications, as a rule, are covered by an irregular strip of plaster, which has a width of 0.02 to 0.03 m. During the time that Rhodes was governed by the grand masters A. Fluvian (1421 - 1437) up to and including P. R. Zacosta (1461 - 1467), particular sections of the fortifications (gate of Saint Anthony, tower of Saint Georgios, tower of Saint Ioannis etc.) have horizontal and

vertical joints which are covered by a strip of plaster with a width of +/-0.01 m, protruding so that the external ends of it are completely straight and obviously cut with the help of a ruler. At the end of the 15 t h century and at the beginning of the 16 t h century, one category of symmetrical wall-construction, with excellent seaming 1 3 and very delicate joints which are difficult to distinguish, becomes fashionable and it appears in secular and church buildings. This type of wall-construction is modeled on the ancient one. In my opinion, it is very likely to be the impact of ideas of the Renaissance. Moreover, an example constructed in accordance with the pseudo-ashlar system 1 4 , has been located in the magazine (beginning of 16 t h century) which stands on the northern side of the Argyrokastro squar. Here, tiles are alternated, so that one has a height of 0.35 m and the other 0.19 m. This type of sophisticated wall-making obviously draws its origin from the ancient Greek models of the Hellenistic period. In this period, as the joints are covered by mortar, this is then engraved with delicate joints with the help of a ruler. During the period of the Turkish empire, from 1522 until 1912, the use of Rhodian sandstone structured according to the ashlar system continues. The Muslim temples 1 5 (of Imprahim Pasha of 1540, of Retjep Pasha of 1588 and of the Sultan Mustafa of 1765), the bath 1 6 of Sultan Mustafa of the 18 t h century, the mausoleums in the burial ground of Murad Reis and other constructions of that period were built with a careful ashlar wall-construction, which approximates that of the end of the 15 t h century and the beginning of the 16 t h century. The same occurred with the constructions, houses and churches, which were built by Greeks in the same period outside of the medieval city in Lindos 1 7.

Limestone does not seem to be used as a construction material in the medieval city until the period of the Italian empire, in other words until 1912. Generally, on the island of Rhodes, it was used in this way in areas where it was abundant. The Early-Christians constructions at the location of Charaki of the village Malona and the medieval Castle of Faraklos in the same area have been built with limestone, because the hill of Faraklos had been formed from this material. The same could be said for the medieval Castle of the village of Archaggelos and the village of Asklipeios . Limestone, of course, as everything else, was used for the production of asbestos, which will be discussed later. Marble 1 8 had a limited use in construction. As a rule, it was placed on door threholds, it framed the rectangular windows of the firearms in the fortification, it covered, in the form of slabs, the floors of courtyards and largely it was engraved with coats of arms or epigraphs which were enwalled in buildings and in the fortifications. Marble tombslabs, which were carved, usually in the image of the deceased accompanied with epigraph which declared the name of the deceased, his rank and date of death, covered the graves of the knights , and also the prosperous townsmen of the city. Marble as a rule, was derived from the ancient ruins of the city or from its cemeteries. Marble, just like limestone, was used during the Middle Ages, but also during the period of the Turkish empire and as an asbestos production material. Again we will discuss this later.

The roadway of the greater number of streets and squares of the medieval city until the middle of the decade of 1950 approximately, was covered by a layer of sea shells cohesively set in clay. The same occurred with the courtyards and the covered areas of certain buildings. Archaeological research has indications, but not certain proof, that in the Middle Ages the pebble also had the same use, at least on particular central roads, in courtyards and ground-level areas of certain buildings.

The use of wood during the Middle Ages does not differ from that of the Hellenistic years. It was used to make furniture, door or window frames, lintels for doors or windows , ceilings (as a rule, on the storey and often on the ground floor) and during the period of the Turkish empire for covered wooden balconies plaster mainly for front faces of the storey, in other words thin partitions made of timber and plaster and girders.

The forests of Rhodes were always rich. Trees which were appropriate for construction grew in them, such as pine trees, cypress trees and cedars. One of the reasons why the Arabs, during the early Byzantine period, sought to take over Rhodes was the desire to be supplied with valuable wood for the construction of their ships. Cedar wood was also obtained by Rhodians from the Asia Minor during the period of the Turkish empire. A ruthless enemy of wood is the climate of Rhodes, damp and hot, which favours the development of pernicious organisms in wood.

We will not particularly dwell on the use of metals, iron. Brass and lead in construction. They had the same use as in antiquity. The medieval Rhodians made tools, nails, railings, gate casings, joints, pegs etc.

The historic sources have not enlightened us, at least not yet, on their origin, if, in other words, the metals were imported from other countries or if some of them at least were mined as ore by Rhodes or other islands of the Dodecanese. The only thing we do know is that there was an attempt by a certain Ioannis de Riparia 1 9 in 1441 to locate gold, silver, brass, iron, and lead ore etc. However, nothing is known about the result of the search. Nevertheless, there is some information that during antiquity there was at least the exploitation of lead deposits 2 0 .

According to the research carried out in Rhodes, Kos, Leros, and Kalymnos, bricks were used in the construction of domes and cupolas during the Early-Christians years. In particular, Rhodian bricks were certainly of the finest, if not the finest in the whole of the Byzantine Empire, due to the fact that they had been selected for the construction of the dome of St. Sophia in Constatinople. Ioustinianos sent three prefects to Rhodes (532/37) in order to make «large, hollow, porous, thin, and white bricks) there; the post of five bricks is situated at one of our own bricks 2 1 » .

When in 562 , under the reign of Ioustinos, the dome was damaged, they used Rhodian bricks again 2 2 . We have only one preserved example from the mid Byzantine period, at the Castle of old Pelio 2 3 . The bricks were also surely during the period of reign of the knights, since there is mention of importing of bricks to Rhodes from Astypalea a document of the Hospitaller knights, from the Maltese records, dated 1452 2 4 . The excavational research, to date, has only located their use in the construction of the sugar processing workshop, located in zacharomylos of Malona. Excavational research has also indicated that they were used in the flooring of a tomb at St. Spyridonas in the medieval city. Baked clay tiles, originating from the workshops in Italy and Spain, were used by the Rhodians in the late 15 t h and early 16 t h centuries in order to cover the flooring of luxurious parlors in the Palace 2 5 of the Grand Masters and the homes of the rich bourgeois of Rhodes.

Rooftop tiles, whether wooden or arched, were used during the whole of the Hellenistic and early-christian period. During the period of knights, the social buildings of Rhodes have a flat roof. The rest of the buildings are , by then, covered 2 6 with a wooden roof, with a coat of concrete with broken brick. It is likely that the homes of the poor were covered with the green clay, the clay which was used as a rule during Turkish domination and until a few decades ago. The ecclesiastic monuments which continued to be arched and domed, where coated with plaster upon which roof tiles were placed. Neither the historical sources nor the archeological research has located any roof tile construction workshops until today.

Plaster, as an adhesive material, became essential to the construction of walls from the early-christian period. Often walls are built with simple clay (earth and water), mentioned in Byzantine documents of the 11 t h century as «stone and clay built 2 7 » which was followed by joining or coating with lime mortar. Nevertheless, the forts and important buildings in the medieval city of Rhodes, especially of the period of knights were built by use of lime mortar as an adhesive material , the walls were therefore «rustic 2 8 » . The plaster was a mixture of lime and sand or other materials.

The lime was made by burning limestone, but they preferred marble because it produced a product of excellent quality. Lime furnaces are often located in archaeological grounds. The sensitive humanitarian knight Sabba da Castilione (1480 - 1554) arrived on Rhodes in 1505 and, acting as an agent to the marquise of Mantova, Isabella Conzaga d' Este, sent her ancient status which he collected from Rhodes and the Alikarnassos area. In the letters accompanying the ancient works of art, he accuses his fellow knights of being barbarians who know nothing more than to use a sword and wear the iron armor; he is terrified at the idea that an ancient sarcophagus, which had just been found at Petroumi (today called Budrum), might be turned into lime to be used for constructional purposes by the commander of the Cast le 2 9 .

In the written agreement , made in November 1453, between the Knights and the leaders of the people of Nisyros, the people of Nisyros request that the Grand Master sends them a foreman in order to build a new large castle, as well as a craftsman for the manufacture of the lime needed for the construction of the new Castle. They pay particular attention to the preparation of lime, which was obviously rare. There is no limestone in Nisyros. Until a few decades ago they obtained it from neighboring Telos.

As mentioned above, another type of mortar frequently used and known from ancient times, was concrete with broken brick, which is a mixture of ground tile and lime. This concrete was processed into an excellent water insulating material which covered domes and flat roofs as well as the internal surfaces of water tanks. During the period of reign of the knights and Turkish domination, it was sometimews used in Rhodes to cover the external surfaces of buildings when they had leakages of rainwater to the interior.

These, in brief, are the materials constituting the medieval city of Rhodes and this is the history regarding their use. The history, comprising many centuries, of the monuments of the medieval city of Rhodes, as well as their endurance to time, partly proves the compatibility of the materials it is composed of. They remain erect and intact, although some are burdened with an age exceeding 500 years, strong earthquakes have shaken them, and they have been hit by the bombardments of the latest large war. We must also bear in mind that they are situated in the unfavorable environment of the damp climate on Rhodes as well as in direct contact with the sea.

•The harmony of the relationship between the construction material was preserved until the first decades of the 20 t h century, that is until the Italian occupancy. The new conquerors of the island were astonished at the sight of the medieval city, facing an environment of western European construction which had hardly been altered in its entirety by time and the slight interventions that had taken place during the Turkish domination. The prevailing conviction of that period, ingrained with the romanticism of the 19 century, not only paid particular attention to the medieval monuments, but also sought their cleansing from all alien to them, later additions and alterations in their construction; builders often «restored» the monuments to their possible initial state. Following this, from the 1920s onwards, after the dominance of the fascist regime in Italy, there were also political reasons that imposed the promotion of the medieval chivalric monuments. Within the general propaganda of the italianation of the Greek population, the conquerors 3 left the material documentation regarding the Byzantine, pre-knightly history in obscurity, whilst signifying that the western European history of Rhodes was a continuation of Italian history which had been intercepted by the Ottoman occupancy.

The Italian regime, acting beneficially, cleaned the fortifications of every foreign body which changed and degraded it aesthetically. They demolished all the buildings which rose above the walls and in front of the sea gate and begun to prop them. Their intervention to the interior of the medieval gate were limited mainly in the region of Collachium, the area in which the members of the knights battalion resided and was concurrently the administration headquarters during the period of knightly reign.

The preservation works to the quarters of «languages» on Knight Street commenced in the 1920s. (The faces of the buildings were cleaned from the coatings, added closed verandahs and all those constructions believed to be foreign to the initial knightly form of the buildings). We will not touch on the subject of the morphological and functional problems of the restoration works here; we will rather focus on the materials that were used.

In referring above to the history of the constructional materials which were used during the middle ages, we mentioned which ones they were and how they were used in Rhodes. Their durability to wear and human intervention has proven their compatibility in practice by now. During the period in question though at the time of the restorations of the medieval monuments of Rhodes, cement had made its appearance, which was then regarded to be a prime constructional material of great possibilities. Obviously, they were not aware of the dangers its use posed to the monuments. Therefore, cement was used on all the monuments of Knight Street, some of them regarded as important works of architecture (quarters of <languages» of Italy, France, Provence etc.). They retained or rebuilt the wooden ceilings and covered the roofs externally with reinforced concrete tiles, whereas during the rule of Knights and Turkish domination, as mentioned above, the roofs were covered with concrete with broken brick or clay. In fact, on the southern side of Knight Street, were some simple, seemingly knightly buildings rise restored, they did not lay a wooden roof; instead they shaped coated roofs with or without balcony. They erected thick beams made of reinforced concrete which occasionally bear underpins made of the same material. The lintels on the openings (doors or windows) of the buildings, where they are coated, have also been constructed with reinforced concrete. The same method has been used wherever it has been necessary to construct girders. By the 1970s, 30 or 40 years following these constructions, the damages of these materials became evident.

Cracks began to appear on the tile veneering and the loadbearing of the buildings, which resulted in the fact that rainwater leaked through to their interior. The damp, among other things, began to destroy the wooden ceilings or, where these did not exist, the veneering fell off the ceilings as a result of oxidation of the expanding iron in the armature of the slate. The same fact is observed with the veneering over the concrete girders or the lintels on the doors and windows.

The plaster used as an adhesive material or as a veneering of the interior areas also consisted of a large quantity of cement. It is possible that this is the reason why, due to the damp of Rhodes, many of these dilate and fall. Where interventions were made on the fortifications, plaster was used as an adhesive, in which they had used a large quantity of cement. The damages are evident at first sight.

The same method, regarding the use of constructional materials, was also used in the «restoration» of the Great Master's Palace, between 1936 and 1940. The result of the use of the materials became evident sooner than the results on the Knight Street buildings. By the beginning of the 1960s, rain water began to flow through the cracked tiling and the roof beams had been affected by decay. Before the roof was insulated in 1998, the guarding staff of the Palace often placed plastic dispensers in order to collect the rainwater which leaked from the ceiling in many of its halls. Wherever there was veneering, it flaked, and the decorative Italian wall paintings fell. When it became necessary to remove the veneering, in 1988, in order to reveal the early Byzantine wall painting of the 17 t h century, we realized that it was approximately 0,10m thick and consisted of a mixture of sand and a large quantity of cement.

Following the incorporation of the Dodecanese into Greece (1947), the Greek archeological Ephorate undertook the important job of restoring the monuments which had been affected by the bombardments of the latest large war, a job which was continued until approximately the mid 1960s. The restoration and supporting of the monuments in Rhodes, as well as the other islands of the Dodecanese, was continued at a tireless rate. By approximately the early 1980s, cement continued to be used, at least as an adhesive material in construction. We must bear in mind that, until approximately the mid of 1970s, the Archeological Ephorate maintained the monuments, following one-sided scientific analysis and report of the archeologist, due to the fact that they did not employ a scientific technical staff. The methodology was not only Rhodian but Panhellenic in the least. The opinion of the experienced and reliable technician was decisive in the use of the constructional material, especially regarding plaster and the facing of static problems. It was natural for the craftsman to be influenced by the current modem notion regarding the construction materials.

I believe that the conclusion volunteers itself: The Rodian monuments require a study of, among others, the medieval materials, especially the plaster, due to the fact that we made errors in that particular area. Ever since the Italian domination, lime mortar was abandoned as an adhesive and as a coating/veneering; cement was used instead, in both the above cases. Contrary to this, the tradition of coating domes with concrete with broken bricks, was preserved by the Greek Archaeological Ephorate.