Mar Yakov Church or Mor Yakup Church (Turkish: Mor Yakup Kilisesi), also known as Church of Saint Jacob in Nisibis, is a historic church in Nusaybin, southeastern Turkey. Archaeological excavations revealed that the 4th-century church building was originally the baptistery of a cathedral, which no longer exists. It is not determined whether this church belonged to Syriac Orthodox Church or the Church of the East.
History
The historical church is located in Nusaybin ilçe (district), formerly Nisibis, either of the Mardin Province of the Syriac Orthodox Church or the Nisibis province of the Church of the East, in southeastern Turkey. It is situated around 100 m (330 ft) east of the Zeynel Abidin Mosque Complex. The church is dedicated to Syriac Jacob of Nisibis, who became bishop of Nisibis by appointment of Episcopal congress, convened in Virgin Mary Church of Diyarbakır in 309, and was later venerated saint (Turkish: Mor Yakup). The church was built by Jacob of Nisibis between 313–320. It is considered as one of the oldest churches in Upper Mesopotamia.
According to some inscriptions and texts, the church was built as the baptistery of a cathedral at that place. However, it was converted to a church after the cathedral and some other buildings were ruined
Architecture
A view from the interior of the Church of Saint Jacob
Tomb of Saint Jacob of Nisibis
The church building features the characteristics of the Late Roman and Early Byzantium architecture. It consists of two sections.
In the southern building, there are two separate parts with two opposed buttresses. A square place of 7 m × 7 m (23 ft × 23 ft) with two doorways in the northern and southern walls is situated in the eastern part. Its eastern wall has an apse. On the west side, an arch opening leads to the western part of the southern section. The eastern part features wall decorations and friezes on the arches and apse's niche. Corinthian helmets decorate all the buttresses except those facing west. It is likely that the middle and western buttresses were added later. The western part of the building has arched doors decorated with fine ornaments in the northern and southern walls. Eight of the doors in the northern and southern walls have horseshoe-like arches. The arches and the pillars are decorated with ornaments. An inscription in Ancient Greek found on the middle frieze reads: "This baptistery was built with the contribution of priest Akepsyma in 571 (359/360), when Volagesus was metropolitan. Let them be remembered before God". A dome, dated back to 1872 according to an inscription of it, covers the eastern square room. A chamber was added on the western side the same year. Beneath the eastern square room's floor, there is crypt containing a sarcophagus, which is believed to belong to Mor Yakup.
The northern section of the building was constructed by using the north wall of the southern section. The construction method of the buttresses in this section, which is also observed in many church buildings in Tur Abdin in the same region, indicates that this part was built in the 8th century. It has the dimensions 7 m × 9.5 m (23 ft × 31 ft).
A third nave is situated on a mosaic-covered platform in front of the southern section.