From the earliest period of Christian history, contacts and interaction existed between Egypt and the Syriac world. For some of the Coptic writings of the Nag Hammadi Library, such as the Gospel of Thomas and the Gospel of Philip, the existence of a Syriac original has often been presumed, going back to the 2nd cent. Even if such a Syr. original once existed, it is unclear whether the Coptic translation would have been made directly from Syr. or from a Greek intermediary. For the five Coptic Odes of Solomon that are incorporated in the Gnostic collection known as ‘Pistis Sophia’ (generally dated to the 2nd half of the 3rd cent.), the source language was almost certainly Greek (regardless of whether the Odes were originally written in Greek or Syr.). Some Coptic Manichean texts, however, were translated directly from a (lost) Syr. original, and recent discoveries in the Dakhla oasis have provided fascinating evidence of the immediate coexistence of Coptic and Manichean Syr. (or at any rate an Aramaic dialect, very close to Syr. in both language and script). The Dakhla findings include, among other things, some wooden tablets with a Syr.-Coptic glossary (ed. Franzmann).

Within the Christian Roman Empire, contacts between Christians in Egypt and in Syria and Mesopotamia intensified. Egyptian desert asceticism attracted interest and visits from Syr. Christians, and several writings about the Desert Fathers became known in Syr. as early as the 5th cent. It is very telling that the later Syr. tradition of the Life of Ephrem lets Ephrem travel to Egypt and spend several years in Scetis, where he met with Bishoi, one of the founders of Coptic monasticism (a legend that lives on in Dayr al-Suryān to the present day). This should be seen as part of the process of ‘egyptianization’ of Syr. asceticism (Becker), which tended to legitimization in the Egyptian tradition of desert asceticism, by giving precedence to texts and persons of Egyptian origin, by re-identifying the authors of existing works as Egyptians, and even by inventing Egyptian founding fathers of asceticism, such as Mar Awgen.

In the development of Christian doctrine, the patriarchates of Alexandria and Antioch played an equally important role. Tensions between the two patriarchates, however, came to the fore and formed much of the background against which the Council of Ephesus (431) was held, which was seen as a victory for Cyril of Alexandria over Nestorius, the latter being associated with Antiochene Christianity. In the wake of the Council, however, reconciliation between Antiochene and Alexandrian bishops took place (433). The subsequent Christological debate brought many Egyptian and Syr. Christians closer together in their rejection of the two-nature formula of the Council of Chalcedon (451), to which they opposed the ‘Miaphysite’ doctrine of the one nature in Christ, in which both the full humanity and full divinity are preserved. While both Egyptian and Syr. Christians were divided between Chalcedonians and anti-Chalcedonians, the latter were able in the course of the 6th cent. to build a church structure that became the foundation for the Miaphysite Coptic Orthodox Church in Egypt and for the Miaphysite Syr. Orth. Church in Syria. They did so in defiance of the imperial authorities who, after some hesitation in the late 5th and early 6th cent. resolutely chose for strict adherence to Chalcedon with the accession of Emperor Justin I (518). Severus, since 512 Miaphysite patr. of Antioch, fled to Egypt in 518, where he not only continued to lead the Syr. Orth. community, but also forged a strong alliance with the Church of Alexandria, arguing that in times of oppression the two Churches needed to act as one. Severus won for himself lasting authority in both the Syr. and the Coptic churches. At his death (538), the Syr. Miaphysites turned for leadership to Theodosius, the exiled patr. of Alexandria who lived in Constantinople, thus again giving expression to the idea that the Miaphysites in Egypt and in Syria should be united. It was only in the late 550s that attempts were made to reestablish an independent Syr. Orth. patriarch. Towards the end of the 6th cent., a theological dispute broke out between the Egyptian Patr. Damian (569–605) and the Syr. Orth. Patr. Peter of Kallinikos (581–91). This was healed only in 616 by Patr. Anastasius of Alexandria (605–16) and the Syr. Orth. Patr. Athanasios I Gamolo. By that time both the Syr. and the Coptic Miaphysite churches had fully adopted Severus’s theology as their foundation (rejecting the teachings of Julian of Halicarnassus, which enjoyed a certain degree of popularity throughout the 6th cent.). Although the Coptic and Syr. Miaphysite Churches henceforth existed as separate churches, there was full doctrinal agreement, which opened the way to different ways of contact and interaction. Particularly important was the exchange of a ‘synodical letter’ at the election of a new patriarch, expressing and reaffirming the communion between the two Churches. Throughout the 6th cent. the language of communication between the Alexandrians and Antiochenes was Greek, and the Coptic translations of Severus’s oeuvre are based on the Greek originals, not on the Syr. translations. In the early Islamic period, the language of communication quickly became Arabic, while Syr. and Coptic continued to be used within the individual churches.

The absence of any dogmatic barrier made it possible for Syr. Christians to fully integrate into the Coptic Church. This happened on different levels. On the highest level, four Christians of Syr. origin or descent served as patr. of the Coptic Church (Damian: 579–605; Simon  I: 692–700; Afrahām b. Zurʿa: 975–78; and Murqus b. Zurʿa: 1166–1189), while a fifth Syrian, the monk Samuel, was close to being elected in 1092 (Den Heijer 2004). It is not uncommon in the colophons of Syr. mss. (mostly but not exclusively in those written in Egypt) as well as in Syr. inscriptions to find references to both the Syr. and the Coptic patriarch (Kaufhold). Monks of Syr. origin lived in various monasteries in Egypt, where they sometimes produced Syr. inscriptions, and collected or wrote Syr. mss. Some of these monasteries are explicitly mentioned in colophons of Syr. mss., such as the Monastery of Mar Michael, in Upper Egypt, where ms. Brit. Libr. Add. 14,582 was produced in 816; an unnamed monastery in the Thebais where in 822/23 the monk Ahron, from Dara, produced ms. Brit. Libr. Add. 14,623 (reusing a 6th-cent. ms. that contained Ephrem’s ‘Prose Refutations’); the Monastery of Mar Yonan, from where around the middle of the 9th cent. three monks brought 10 mss. (ms. Brit. Libr. Add. 14,623 being one of them) to Dayr al-Suryān; and the well-known Monastery of St. Paul, near the Red Sea, where ms. Brit. Libr. Or. 5021 was produced at the end of the 9th cent. (Brock 1995). The traditional historiographies of the Coptic and the Syr. Orth. Churches (in particular the Arabic ‘History of the Patriarchs of Alexandria’ and the Syr. Chronicle of Michael Rabo) pay much attention to developments in the sister church. Among the Syr. Orth. patriarchs with particular interest and contacts in Egypt, Dionysios of Tel Maḥre and Quryaqos should be singled out. The Syr. Orth. never set up their own hierarchy in Egypt, even if they had some Syr. churches for their communities (Den Heijer 2004, 935–36).

A clear example of the proximity and the interaction between the two Churches is the creation and millennium-long existence of Dayr al-Suryān. After Syr. Orth. monks (in the first period mainly from Tagrit) settled in the monastery in the second decade of the 9th cent., they lived together with Coptic monks. The inscriptions and wall paintings in the monastery clearly attest to the coexistence of the two communities, Syr. and Coptic, and from the 11th cent. onwards the scriptorium produced Coptic and Arabic mss. (along with the Syr. ones, which started being written in the monastery no later than the 10th cent.). While the status of the monastery between the Coptic and Syr. world has received much attention in recent scholarship, the disappearance of the Syr. element in the early 17th cent. should be seen rather as the gradual absorption of the Syr. monks into the mainstream of Coptic life than as a radical linguistic or cultural shift within the monastery’s population (Den Heijer 2004, 937).

While the Syrians’ familiarity with the main theologians of the Alexandrian tradition (such as Athanasius, Cyril, Timotheos, and Theodosius) and with the main texts of Egyptian asceticism was primarily based on Greek texts, there is some evidence of translation work from Coptic into Syriac. A Bohairic Coptic original underlies the extant Syriac Life of Macarius (Toda). Evidence of translation work carried out at the beginning of the 10th cent. by Yuḥanon bar Maqari, the abbot of Dayr al-Suryān, may be found in Syr. ms. Dayr al-Suryān 30. In this ms., partly written by Mushe of Nisibis (the later abbot), Yuḥanon is credited with the translation ‘from the Egyptian tongue into Syriac’ of the Life of the Roman brothers Maximos and Dometios (unpublished) and of the Life of Macarius (ed. P. Bedjan, Acta martyrum et sanctorum, 5 [1895], 177–262). The same Yuḥanon left a note in Coptic in Syr. ms. Brit. Libr. Add. 14,635 (f. 5r), a ms. with extracts from Evagrius of Pontus, which he helped bind in 894, when he already was abbot. The Syr. impact on the Coptic liturgical tradition is significant. Many Syr. saints were adopted in the Coptic Church: in addition to Severus of Antioch, two major Syr. saints, Barṣawmo and Shemʿun the Stylite, are represented in the Coptic Synaxarium (Farag) and are depicted in Coptic art; many more are listed in Coptic martyrologia and liturgical calendars (Fiey 1972–1973, 305–10). Some extracts from Ephrem and Yaʿqub of Serugh are preserved in a dogmatic florilegium that may go back to Coptic sources, but is preserved only in Arabic and Ethiopic (Graf 1937). A number of translations from Syriac into Arabic were carried out in Egypt; some of them can be located in Dayr al-Suryān in the 15th–17th cent. (Graf 1951, 23).

While the present overview has focused on the Coptic contacts with the Syr. Orth. Church, E.-Syr. Christians traveled to Egypt as well, either as pilgrims and visitors (e.g., Aba I, Abraham of Kashkar, and ʿEnanishoʿ) or for a longer stay. Around 700, an E.-Syr. bp. is attested for the E.-Syr. diaspora in Egypt, but shortly after his consecration he fell into the hands of Bedouins and was reduced to slavery for the remaining 40 years of his life. Other bps. are attested in the 10th and 11th cent. (Fiey 1972–1973, 338–340). E.-Syr. authors who became popular in the Coptic Church include Isḥaq of Nineveh and Yoḥannan of Dalyatha (‘the spiritual elder’), but their works were translated from Syriac directly into Arabic.

In the 19th cent. a Syr. Catholic hierarchy was set up in Cairo, while a Chaldean diocese, based in Heliopolis, was created in 1980. In the worldwide diaspora the Coptic and Syr. Orth. communities often work together. The British Orthodox Church, whose episcopal succession was partly Syr. Orth. in origin, was given a home in the Coptic Orth. Church in 1994.

A promising field of study may be the comparative study of the Coptic and Syriac language and syntax, as the two languages developed under similar conditions and were both exposed to the influence of Greek. Among the few features that have received some attention is the Syr. structure (occurring from the early 6th cent. onwards) consisting of the verb ʿbad ‘to do’ followed by the Greek infinitive (e.g., ʿbad filosofise ‘to philosophize’), which parallels, and may be derived from, a similar structure existing in all Coptic dialects except Sahidic, and which consists of the verbal form -er ‘to do’ and a non-conjugated form of the Greek verb (e.g., Bohairic er pisteuin ‘to believe’) (most recently Brock 2004 — for a different explanation, however, see C. A. Ciancaglini, ‘L’origine delle locuzioni verbali con ʿbad in siriaco’, in Loquentes linguis. Studi linguistici e orientali in onore di Fabrizio A. Pennacchietti, ed. P. G. Borbone et al. [2006], 173–84).

See Fig. 19, 37, 38, 58, 89, 90, and 113.