Essential Architecture-  Turkey

Saint John The Baptist in Trullo, Achmed Pasha Mesjedi




Istanbul, Turkey


12th century.




Brick, originally tile roof, later lead roof.


Present-day Mosque, former Church
The smallest Byzantine church of Constantinople (Hirami Ahmet Pasha Mosque)

Hirami Ahmet Pasha Mosque (Turkish: Hirami Ahmet Pasa Mescidi) is a former Eastern Orthodox church converted into a mosque by the Ottomans. The small church, one among the 36 dedicated to Saint John the Baptist in Constantinople, was part of a monastery bearing the same name. Its full name was Saint John the Forerunner by-the-Dome (Hagios Ioannis ho Prodromos en to Trullo). It is the smallest Byzantine church of Constantinople still extant and has never been studied.

The building lies in Istanbul, in the district of Fatih, in the neighborhood of Çarsamba, one of the most (Islamic) conservative areas of the walled city. It is located in Koltutçu Sokak, along a small square, surrounded by new buildings, less than 400 m to the south of the complex of the Pammakaristos.

Nothing is known about this church before the conquest of Constantinople in 1453. The appellation “troullos” (Latin trullus, Italian trullo, dome) probably comes from a dome-roofed palace that used to be in the neighborhood. According to its style, the church must have been built during the 12th century.

Between 1454 and 1456, when the Patriarchate was moved from the Church of the Holy Apostles to that of Pammakaristos, Patriarch Gennadios displaced some nuns who were living in the monastery of Pammacharistos to the small nunnery of Troullos, which probably was founded in this occasion. At the end of 16th century, during the reign of Sultan Murat III, Hirami Amet Pasha, formerly Agha of the Jannissaries, converted the church of the Pammakaristos into a mosque. He did the same with the church of Saint John, closing the nunnery and expelling the nuns. This should have occurred between 1587/88 (the years of the conversion of Pammakaristos) and 1598, the year of his death. At the beginning of the 20th century, the small building went to ruin. In 1961, it was carefully restored and reopened to Islamic worship

The building is built of masonry made with bricks and stone. It has a cross-in-square plan surmounted by a dome, with a bema divided in three parts and a narthex. It is only 15 m long, included the narthex. The arms of the cross to the north and south are covered with barrel vaults, and the interior is lighted by triple windows. Four columns with capitals sustain an octagonal drum, which bears the dome. The three apses are semicircular. The central apse projects outside, and is opened by a large window, divided in three parts by two pillars with capitals. The diaconicon has been reused as mihrab of the mosque. The prothesis is surmounted by a barrel vault. The mosque has no minaret.

Before restoration, the building was in a very bad condition: the narthex was almost completely ruined, the columns had disappeared, and the paintings were barely visible. The four missing columns have been replaced with ancient ones, whose origin is unknown. The edifice has never been the subject of a systematic study.

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The identification of the church of S. John the Baptist in Trullo with the mosque of Achmed Pasha Mesjedi is based on two reasons: first, because of their common proximity to the church of the Pammakaristos, now Fetiyeh Jamissi; secondly, on the ground of the tradition current in the Greek community on that point. The latter reason is in this case particularly strong, seeing the church of the Pammakaristos was the patriarchal cathedral almost immediately after the Turkish conquest, and retained that honour until 1591. The highest Greek ecclesiastical authorities were therefore in a position to be thoroughly acquainted with the dedication of a church in their close vicinity. In 1578 the protonotarius of the patriarch showed Gerlach the site of the Trullus close to Achmed Pasha Mesjedi.


The church is mentioned in history only by Phrantzes, who informs us that when the Patriarch Gennadius transferred the patriarchal seat to the monastery and church of the Pammakaristos, certain nuns previously accommodated in that House were removed to the neighbouring monastery of S. John Baptist in Trullo. Phrantzes explains the designation of the church, 'in Trullo,' as derived from a palace named Trullus which once stood in the vicinity to the north of the Pammakaristos. It was the palace, adds the historian, in which the Council of Constantinople, known as the Concilium Quinisextum (Πενθέκτη), or the second Concilium Trullanum, assembled in 692, in the reign of Justinian II. But the palace Trullus, in which the first Concilium Trullanum met in 680, was one of the group of buildings forming the Great Palace beside the Hippodrome, and there the second Concilium Trullanum also held its meetings. Phrantzes is therefore mistaken in associating the Council of 692 with a palace in the vicinity of the Pammakaristos and Achmed Pasha Mesjedi. But his mistake on that particular point does not preclude the existence of a palace named Trullus in the neighbourhood of the Pammakaristos. In fact, the existence of such a palace in that district is the only possible explanation of the attachment of the style 'in Trullo' to a church on the site of Achmed Pasha Mesjedi. Nor is it strange to find a name pertaining primarily to a building in the Great Palace transferred to a similar building situated elsewhere. The imperial residence at the Hebdomon, for example, was named Magnaura after one of the halls in the Great Palace. There was an Oaton or Trullus in the palace of Blachernae, and in the palace at Nicaea. Consequently, a palace known as the Oaton or the Trullus might also be situated near the Pammakaristos, to command the fine view from  that point of the city. Mordtmann, indeed, maintains that the building to which Phrantzes refers was the palace at Bogdan Serai, the subsequent residence of the Moldavian hospodar in Turkish days, and that the church of S. John in Trullo was not Achmed Pasha Mesjedi, but the church of S. John in Petra (Kesmé Kaya) beside that palace. This opinion, however, is at variance with the statements of Phrantzes and Gerlach. Furthermore, the designation 'in Petra' was so distinctive a mark of the church of S. John near Kesmé Kaya, that the church could scarcely have been recognised under another style.


S. John in Trullo, from the south-west.

S. John in Trullo, from the south-west

Balaban Mesjedi. Interior view.

Balaban Mesjedi
Interior View.

Details from the Church—Details from the Pammakaristos—Details from the Pantepoptes.

Fig. 68.

Architectural Features

S. John in Trullo belongs to the ordinary 'four column' type of church building, and has a narthex. Its three apses are semicircular both within and without, presenting the only instance in Constantinople of apses semicircular on the  exterior. The central apse projects m. 3 beyond the body of the building, and was lighted by a large but low window, divided into three lights by two pilasters crowned with carved capitals; the diaconicon has been built up to form the mihrab of the mosque; the prothesis, to the north, has a barrel vault.

Details from S. Andrew in Krisei—Details from the Chora.

Fig. 69.


The drum dome is octagonal, with eight ribs and as many windows. It seems large for the size of the church, and is lower than usual inside. The windows do not cut into the exterior cornice of the dome. Originally the dome arches rested on four piers or columns, but these have been removed in the course of Turkish repairs, and the dome arches are now supported by beams running across the church, under the impost of the arches.


The arms of the cross to the north and south have  barrel vaults, and the walls are pierced by triple windows. Two capitals built into the exterior face of the northern wall, and marked with a cross, were doubtless the capitals of the shafts which divided the northern window into three lights. The western arm of the cross is covered by the roof of the narthex, and lighted by a small round-headed window above it. The small narthex is in three bays, covered with cross-groined vaults.


It is not probable that the church was converted into a mosque before 1591, when the patriarchal seat was removed from the Pammakaristos to S. Demetrius beside the Xyloporta. Nor could the conversion have been later than 1598, the year in which Achmed Pasha—who converted the building into a mosque—died.

 Plans and sections of of S. John in Trullo and S. Thekla.

Figs. 70 and 71.

Text quoted from-
Byzantine Churches in Constantinople, Their History and Architecture.
MACMILLAN AND CO., Limited, London, 1912.
by Alexander Van Millingen and Ramsay Traquair and W. S. George and A. E. Henderson.