1. The Cross-Domed Church in the Framework of the Byzantine Ecclesiastical Architecture

The Dormition Church of Nicaea in Bithynia is a cross-domed church, an architectural type which to a great extent is a transitional type between the Justinianean domed basilica¹ and the typically Byzantine styles of the ‘cross-in-square’² and the ‘octagonal’ church.³ As a result, it is a milestone for the general development of the Byzantine ecclesiastical architecture, which has early on begun to abandon the type of the oblong basilica type of devotional building, which was the Early Christian dominant architectural type throughout the Mediterranean, in an attempt to express in a functional way the new perceptions on both the liturgical space and the ritual of worship. The ritual of the East with the long processions of priests, which required oblong devotional buildings, were replaced relatively soon by circular processions, which required different architectural types of church. This change was followed by similar changes in the theological proposals defining the way a devotional building should be constructed. Thus, as early as in the 6th century, the oblong type of church, although it did not completely disappear, gave gradually way to a building with a more compact plan, which is actually constructed around a square central core supporting a vault. In a word: the central space, which was covered by the dome, became the fundamental part of the entire building.⁴ The ideological ferment of the period of Iconoclasm (726-843) followed this development and theoretically supported the relative changes.

2. Description of the Church and Main Stylistic Characteristics

Although there are several forms of church building which express the above tendency towards the transition to the Byzantine architectural types of central plan, that is, the cross-in-square and the octagonal church, it may be assumed that the cross-domed church shows this tendency more clearly. The ground plan and the cross section of the Dormition Church in Nicaea reveal some of the main characteristics of this type:

a) Four massive pillars dominate and mark the corners of a central square core.

b) Four small rectangular spaces of the same depht and barrel-vaulted are formed on the sides of the central square, and a cross is thus formed.

c) Four smaller pillars, two on either side, form two arcades leading to two side compartments (the side aisles). Another two compartments on the two other sides of the central square serve as a narthex and bema respectively.

d) The four compartments are covered by semi-cylindrical barrel vaults. The three of them (the two side aisles and the narthex) have galleries (second floor), which are also covered by semi-cylindrical barrel vaults. A drum with only a few windows bears, with the help of spherical triangles (pendentives), the dome crowning the central square core.

e) Four smaller compartments in the corners complete the entire building: on either side of the narthex and on either side of the sanctuary (parabemata). These compartments are fully inscribed in the overall square ground plan of the church (one of them, the diakonikon, was covered in the 19th century by a prismatic small cupola, which was not included in the original design). All the spaces of the lower floor have direct access to the neighbouring spaces through small or large openings.

f) Both the sanctuary and the parabemata end in apses, semicircular on the inner side and semi-hexagonal on the outer side.

g) The two side aisles and the three galleries communicate with the central core of the building through arcades, while the narthex is isolated behind a wall with only one door. Because of this characteristic, which gives the impression that the central core of the building, both on the ground and the upper floor, is surrounded by stoes, the term ‘church with a peristyle’ is sometimes used instead of the term cross-domed church.

3. History of the Research on the Dormition Church of Nicaea

The Church of the Dormition has been destroyed. It was built on the SE side of the city and was preserved until September 1920, when, because of the events of the war in Asia Minor, it was looted and burnt during Turkish vandalisms. The church was pulled down in 1922. Only the floor and the lower parts of the walls and the marble pillars survived. However, before that, the church had been systematically investigated and extensively photographed, while its ground plan had been drawn by two scholars, the German Otto Wulff and the Russian Theodor Schmit, who presented the scientific community, in 1903 and 1927 respectively, with the results of their research (the research of Schmit was carried out in 1912 and included photographs and drawings of N. K. Kluge). Before them, two well-known and important scholars working on the Byzantine archaeology and art, Josef Strzygowski (1892) and Charles Diehl (1892), had already investigated, though less systematically, the monument and its valuable mosaics. Much later, in 1955, an excavation was carried out in the area, which revealed some remains (floor, masonry and some relief parts) that survived the catastrophe of 1920.

4. Other Cross-Domed Churches

Although the church was destroyed, valuable information about this monument, part of a group with very few members, has been preserved thanks to these European pioneers of Byzantine studies. It should be pointed out that few original cross-domed churches are known today. Apart from the Dormition Church in Nicaea, this group includes the church of Hagia Sophia in Thessaloniki, which is still preserved, although with several later alterations (today restored by the Greek Archaeological Service), as well as two churches in Constantinople: the so-called Kalenderhane Camii (possibly the Byzantine Panagia Kyriotissa) and the Gül Camii (formerly believed to be the Byzantine St Theodosia but today identified with the monastery of Christ Euergetes). Among the very few examples of the family of cross-domed churches, only the church of Thessaloniki has been preserved intact. There are slight differences among these four buildings. These differences seem to be variations on a common theme rather than evidence indicating some development in the particular architectural type.

5. Chronology of Cross-Domed Churches and Origin of the Style

There is no direct evidence about the exact date these four churches were built. They have been indirectly dated, according to information about the construction or their mosaic decoration (Hagia Sophia, Dormition), although there have been different opinions concerning this attempt. The cross-domed building of Hagia Sophia has been dated to the early 7th century,⁵ the early 8th century⁶ or even the late 8th century.⁷ On the other hand, the Dormition Church in Nicaea has been dated to the late 6th century,⁸ the early 7th century,⁹ between the late 7th and the early 8th century¹⁰ or to the 8th century.¹¹

As regards the connection between the two buildings, scholars tend to accept that Hagia Sophia of Thessaloniki was probably built after the church of Nicaea, as it is a more refined construction and a more ‘elaborate’ version of both the overall arrangement of space and the connection among its separate architectural parts. This is also indicated by the dimensions of the two monuments. Hagia Sophia is an imposing building measuring about 44x38 metres, with a cupola about 10 metres in diameter, while the Dormition was about half the size of the first church (22.5x21 m, with a cupola about 6 m in diameter). On the other hand, as regards the two preserved cross-domed churches in Constantinople, Gül Camii dates to the period between the early 11th and the late 12th century¹² or, more precisely, from circa 1100,¹³ while Kalenderhane Camii dates to the 12th century¹⁴, or, more precisely, to the late 12th century.¹⁵ This means that the two churches in Constantinople are later forms or ‘revivals’ of the cross-domed church and, as a result, they must somehow differ from the churches of the Dormition in Nicaea and Hagia Sophia in Thessaloniki, which are the only preserved ‘original’ examples of this style, coming from the period this type first appeared. Moreover, the Dormition Church in Nicaea must have been the earliest example of this type.

However, it should be underlined that probably there were more churches of this type, perhaps earlier than the church of Nicaea (particularly in Constantinople), although no remains have survived. There are still some churches in north Mesopotamia and Antalya, on the south coast of Asia Minor, which are highly reminiscent of the cross-domed church and date to the late 6th century, which is earlier than the Dormition Church in Nicaea. Given that throughout the 7th century the attention of Constantinople was directed to the East because of the Arab threat, it is possible that the specific architectural type was transferred from these eastern regions to Constantinople, where it was further developed by imperial architects. Then it was transferred again to the provinces, although a little changed, towards the late 7th century and the early 8th century, represented by buildings like the churches in Nicaea and Thessaloniki. Whatever the case, the question of when and where the type of the cross-domed church was introduced remains open.

6. Historical Background of the Dormition Church

The Dormition Church must have been originally intended to serve as the katholikon of a monastery. It seems that a certain abbot Hyakinthos was the founder of the church. There is a devotional inscription of the abbot written on a parapet, while monograms of the same priest were carved on the anta capitals of the pillars and elsewhere. The abbreviated inscription on the parapet said: ‘ΘΕΟΤΟΚΕ, ΒΟΗΘΕΙ ΤΩ ΔΟΥΛΩ ΣΟΥ ΥΑΚΙΝΘΩ, ΜΟΝΑΧΩ, ΠΡΕΣΒΥΤΕΡΩ, ΗΓΟΥΜΕΝΩ’ ("Mother of God, please help your servant Hyakinthos the monk, priest and abbot"). Although the written sources from the 8th to the 14th century mention the monastery as ‘Monastery of Hyakinthos’, it is almost certain that the church was dedicated to the Virgin Mary when it was built. However, it is not known whether it celebrated on the Dormition day (as in the 19th century) or on a different celebration day in memory of the Virgin Mary.¹⁶ The orientation of the building follows the typical Christian pattern, where the apse of the bema faces the East. The apse had a synthronon. The church was adorned right from the beginning with mosaics (some bearing the monograms of Hyakinthos), some of which were removed during Iconoclasm, before they were restored when the Iconoclastic Controversy permanently ended in 843.¹⁷ The energetic abbot of the ‘Monastery of Hyakinthos’, Gregorios, was first mentioned during the Seventh Ecumenical Council held in Nicaea in 787.¹⁸

The next piece of information connected with the monument refers to St. Constantine the Jew (late 9th century), who came from Nicaea. When he travelled to Cyprus, where he came by the holy hand of saint Palamon, the saint returned to Nicaea and deposited the relic in the church of the Monastery of Hyakinthos.

After the destructions caused by the earthquake that occurred in September 1065, the church was extensively reconstructed: the galleries were removed from the side aisles (not from the narthex) and the arches (which must have collapsed), the base of the cupola and large parts of the narthex were rebuilt. The earlier templon, consisting of marble parapets with crosses, was replaced with a new one. Finally, an exonarthex was added. As soon as the galleries were removed, the lower part of the church must have been flooded with light coming from the three large windows existing in the upper part of each of the side walls (see cross section). Nothing is known about the extent of damages caused to the dome by the earthquake of 1065. Judging from the reports of the Byzantine writer Attaleiates on the damages caused by the earthquake to the city and the walls of Nicaea, it is possible that the largest part of the dome collapsed as well. It seems that by that time the monastery was assigned as pronoia by Emperor Constantine X (1059-1067) to patrikios and megas hetaireiarches, Nikephoros, who restored the church after the earthquake, ordered and funded new mosaics on the narthex (thus replacing the previously damaged) and left an epigram bearing his name on one of them, above the entrance to the main church: ‘ΚΥΡΙΕ ΒΟΗΘΗ ΤΩ ΣΩ ΔΟΥΛΩ ΝΙΚΗΦΟΡΩ ΠΑΤΡΙΚΙΩ ΠΡΑΙΠΟΣΙΤΩ ΒΕΣΤΗ ΚΑΙ ΜΕΓΑΛΩ ΕΤΑΙΡΙΑΡΧΗ’ ("Lord, please help your servant Nikephorus the patrikios, praepositos, vestes and grand hetairiarches").

There is no information about the church from the 12th century on. According to a synodal act of 1209, the particular Synod convened in the ‘outer church’ (probably the exonarthex) of the Monastery of Hyakinthos and the church of the monastery had been assigned to the then Patriarch Michael IV Autoreianos (1207-1213) as his see. It may easily be assumed that the donation to the patriarch had been made by the Emperor of Nicaea Theodore I Laskaris (1204-1222). We may then assume that the church of Hyakinthos was at the time closely connected to the imperial family; besides, all family members were buried there. In 1240, the abbot of the Monastery of Hyakinthos, Methodius, was elected patriarch but died three months later and was also buried in the monastery. After the occupation of Nicaea by the Ottomans (1331),¹⁹ the church of the Monastery of Hyakinthos was the only one that was not transformed into a mosque. The monastery continued to operate regularly as a Christian church and famous Gregorios Palamas, who visited it in 1354, admired its gardens and wells.

The church of the early 20th century, as it appears in the photographs of Wulff and Schmit, is to some extent the result of later restorations. The cupola collapsed in 1803, possibly because of an earthquake, while the church, which was almost deserted, suffered extensive damages. In 1807 the metropolitan of Nicaea, Daniel, started restoration works at the church, which lasted for some decades. A new dome was built in 1840. Minor repairs carried out throughout the 19th century had changed considerably the original image of the church, when it was photographed in the early 20th century.