Located on the Alfof Mountain, known in Arabic as Jabal Maqlūb, 35 km. northeast of Mosul, the monastery is mostly known by its Arabic name Dayr Mār Mattā. It is named after a monk named Matay who came from the region of Amid in the latter part of the 4th cent. It is known from historical documents as early as the late 5th or early 6th cent., when it was already a center of the Syr. Orth. Church. The Chronicles of Michael Rabo and Bar ʿEbroyo record that life resumed at the monastery by the end of the 5th cent. Monasticism took various forms in the monastery, including monks who were ʾabile ‘anchorites’, ḥbiše ‘recluses’, and ʾiḥidoye ‘hermits’, but others preferred communal life. The monastery appears to have had a bishopric line from its early days, whose title often included Nineveh (i.e., Mosul). It was also here that a number of local Synods took place. The bishopric of this monastery was so strong that on many occasions, especially from the 7th cent. onward, the residing bp. would challenge the authority of the Maphrian, to the degree that he became a de facto co-equal to the Maphrian, each of them ruling over half of the Syr. Orth. Church in the East. In 869, Patr. Yuḥanon III held a Synod which reiterated the subordinate position of the Maphrianate of the East in relation to the Patriarchate of Antioch. In addition, the first Canon of that Synod made it clear that the bp. of the monastery is to be subordinate to the Maphrian. Michael Rabo also reiterated this relationship in 1174. The monastery was famous for its magnificent library which is cited in the correspondence of Timotheos I in the 8th cent., and later by Dawid bar Pawlos of Beth Rabban. It is also mentioned in a colophon of a Syriac ms. (Berlin, no. 327) that in 1298 the library contained all the writings of Bar ʿEbroyo. In 1171, the Kurds attacked the monastery and many of the mss. were damaged; some that survived were carried by monks to Mosul. In 1369, another Kurdish attack on the monastery damaged more mss. Today mss. from this monastery can be found in the British Library, Cambridge University Library, Staatsbibliothek, Berlin, and the Vatican Library. The monastery served as the seat for the Maphrian on many occasions. Bar ʿEbroyo spent the first seven years of his Maphrianate here. During the early 19th cent., the Kurds raided the monastery many times, and as a result it was abandoned for 12 years. Later that century, Oswald Parry, a delegate of the Archbishop of Canterbury, visited the monastery and published an account detailing life there. In modern times, the monastery was the venue of the Dayro d-Mor Matay Synod in 1930, the first and only Synod with representation of the laity. The Beth Qadishe of the monastery contains the remains of six Maphrians and many bishops including Bar ʿEbroyo and his brother. The monastery has over 50 rooms, 3 halls for gathering, and a church. To the left of the monastery is a large cave with natural mountain spring water dripping from the ceiling. Today, the monastery is the seat of its own archdiocese.

See Fig. 20, 73, and 74.