Didymoteichon, the old byzantine centre, twice a de-facto capital of the Byzantine Empire, became the first seat of the Ottoman Empire in Europe, after its capitulation in 1361. The Ottoman town was formed outside the castle, since the Christians continued to live inside, according to the terms of the surrender treaty.
The new, Ottoman town was developed around its most important public foundations, first of all the mosques. Its administrative, economic and, of course, religious center was organized around the impressive, sultan Mosque, the Great Mosque.
In 1667 Evliya Celebi mentions the existence of 12 mosques, each one corresponding to a different neighborhood (mahalle). Only one of them, the Great Mosque, has a minaret, being a “cami”, while the others were medjits. In the beginnings of the 20ieth century only seven mosques existed, most of them then with a minaret, as well as some other religious foundations. Today two of them survive, the Great Mosque and the Small or Aladja (=Red) or Sandrvan (=Fountain) or Carci -Pazar Beyli (=Market) cami, which is in function in order to serve the religious needs of the local Muslims and was recently restored by the Municipality of Didymoteichon.
The Great Mosque
According to the tradition the mosque was started to be erected in the end of the 14th century AD by the sultan Bâyazid I Yildirim (Thunderbolt), who lived then in Didymoteichon. The project did not finish in time, due to the invasion of the Mongols in Asia Minor and the following battle of Ankara (20/7/1402), which came out to be disastrous for both, the Ottoman Turks and the sultan himself. Nevertheless, the local tradition recognizes the Mosque as “Bâyazid Camisi”, a tradition that is followed, as well, by the Ottoman travelers. Its other, well known name is “Buyuk Camisi”, the Large Mosque, while Evliya refers to it as the Ulu, that is, again, the Great Mosque.
The foundations of the Mosque are partly projected outside the silhouette of the building, raising conjectures for the existence of a previous foundation in the same place, Christian from the Byzantine period or Islamic, a foundation of the sultan Murad. Such a proposal is plausible, since the holy places were characterized by the continuation of use, independently of the dominant religion. We can add here that according to an old Christian tradition the Mosque had been erected exactly on the place of a church dedicated to St George or St. Sophia, although we already know about the existence of a St. George Palaiokastritis (of the Old Castle) inside the fortification and a St.Sophia church on the place of the post-byzantine church of the Ascension of Virgin Mary.
The dendrochronological investigation, with samples of the upper part of the construction, gives the year 1418, while the large inscription over the main entrance mentions that “the construction of the blessed improved honored Mosque was declared in March, 1420”. A second inscription over the lateral entrance refers to the year 1421 as well as the names of two sponsors of the building and the architect who completed the work, Àwwad Ibn Bâyazid. This person is no other than the famous vizier and architect Haci Ivaz Paşa, who is well known for the erection of monuments such as the Green Mosque (Yeşil Cami) in Bursa, whose plan was going to be followed as well in the planning of the Didymoteichon mosque. Ivaz explored new ways in planning and executing, which led the implementation of the Ottoman mosques to innovative solutions, culminating in the central-dome type. Supervisor of the task in Didymoteichon was Tûghân (Dogan) bin Abdullah Beg, a Christian renegate, the “glory of the engineers (of the Mühendis)” of the empire, responsible as well for the erection of the Bâyazid pasha mosque in Amaseia,. The superior religious judge, the “kadi” of Didymoteichon, Sayyid Ali, was the administrative superintendent for the implementation of the project.
The building is almost square in plan, with average exterior dimensions 32,40*30,20 m, walls of a thickness larger than 2,11 m and with four bulky piers erected in its interior, of a thickness about 2,07 m. The area covered by the building is almost an acre; this was the reason for its use as a measurement unit for the fields of the area.
The building presents two constructional phases. Those are well distinguishable because of the difference between the elegant masonry, consisted of well carved ashlar, applied precisely, almost without mortar or with the intermediate insertion of slim sheets of lead and the hasty masonry from rough and irregular stone of the upper part of the facade. The differentiation of the phases can as well be witnessed in the interior of the mosque, especially on the eccentricity of the projection of the transversal pseudo-arches on the stilted blind arches of the external walls.
Concluding, we think that Bâyazid, indeed proceeded in the ambitious deed of the erection of the Mosque, but his project was interrupted for a large period of time and it was continued by the new sultan, Mehmed I, only after the end of the Ottoman civil war (1413), to be integrated in 1420-21.
The initial constructional plan possibly anticipated the coverage of the large internal space with a system, dominated by two central brick-constructed blind domes, supported by the external walls and only two, instead of four, smaller auxiliary domes, exactly as it was the case with the other Ivaz’s work, the Green Mosque in Bursa. This supposition is supported by the aforementioned local tradition, which connects the mosque with the sultan Bâyazid. Another new view proposes the initial planning with a central type, with lateral minor real domes and barrel vaults.
In any case, the impossibility of the realization of a difficult task (although later it was applied in Fethiye mosque, in Athens) led to the final choice of the erection of four masonry piers in the interior. These piers together with the four walls support a huge wooden pyramidal roof, with an inclination of about 80% (an angle of about 38°) covered with thick sheets of lead, applied on a layer of clay mud, including straw and dung, as well, in order to ensure adhesion and impermeability. These sheets were applied without any nailing, only with their dexterous folding together. The structural and constructional system of the wooden roof, based on the function of four main vertical trusses, with their beams reaching cross-sections of a scale of 0,40*0,50 m is functioning in two levels and can be characterized as a masterpiece of the historical engineering.
The monument has three – all of them exterior- doors. The magnificent frame of the central entrance is decorated with eloquent arabesque and kufique motives, while two other doors sideways of the main entrance have been closed in an early date. As far as it concerns the red and white chevrons, decorating the arches of the entrances, they can meet their relatives in earlier examples, such as the Orhan Mosque, in Bursa.
Until recently the approach to the main entrance was achieved through a grandiose stone stair, which bore a high quality parapet. Besides those, some traces on the facade indicate the initial planning of a portico with three domes in a row. Other traces reveal that later the portico was formed as a simple open hall, covered by a two-sloped roof.
The interior of the mosque is, as well, particularly interesting. The central space is covered by a beautiful decorative blind dome, consisted of small wooden boards, property adjusted between them. The dome is suspended from the wooden truss of the roof, ending down to the four piers through equal in number decorative wooden huge triangles. The floor, on the other hand, was paved with accurately joined hexagonal clay plaques (today covered with plain orthogonal ones), once covered by luxurious, multi-coloured carpets.
Until some years ago it was possible for the visitor to admire a presentation, unique in Islamic art, of a praying woman, described on the northern wall. This wall-painting was, unfortunately, destroyed by the intense moisture and the lack of conservation. Another, equally unique presentation, is fortunately still surviving on the southern wall, over the mihrap, the bema of the mosque. It represents a heavenly city, repeating the theme of the famous mosaic of the Omar Mosque in Damascus. The Didymoteichon wall-painting impresses with its eloquent, exact and detailed treatment of the scenery and especially the buildings, as well as its chromatic spectre, in a direct continuation from the Late – Byzantine painting, proving the true of Jorga’s assertion about Ottoman Empire and culture as “Byzance après Byzance”, since at least 85 % of the maistors, engineers, architects and artists of the Ottoman Empire were Christians, at least until the beginnings of the 16th century, as the Turkish historian Ö.Barkan had set it.
The walls and the piers of the building are also decorated with sayings depicted from the Holy Koran, small prayers and invocations to holy persons, written with thick calligraphic letters in an unusual arrangement. One of those, expressed in a form of a lightning, was considered by the Muslims as preventive of a fall of thunderbolt.
As far as it concerns the equipment of the mosque the minber, the “throne” is still maintained next to the mihrap, while a wooden gallery still stands at its northern part.
Incorporated in the silhouette of the building, but possessing its own entrance directly from the outside, the elegant, very high minaret initially had only a balcony. When the Turks recaptured Didymoteichon from the Bulgarians, in 1913, they rebuilt the highest part of the minaret and added a second smaller balcony.
The yard was enclosed with “marble plaques sideways of the entrance, works of an excellent sculpting art” and exhibited a very interesting fountain. This interesting scenery was destroyed during the works of the “rehabilitation” of the square, in 1980-81.
In 1912 the Bulgarians, who captured Didymoteichon after the outbreak of the Balkan War I, turned the mosque into a church dedicated to St.George. During the ’30ies of the 20ieth century, the mosque was sold by the Muslim community to a businessman and it was used as a ware-house. Today the Great mosque is a cultural monument, protected by the Greek State. It is now that reveals, more than ever, urgent the priority of the removal of the imminent danger of collapse of the roof of the Great mosque in order to be followed by its integrated restoration and its proper promotion.