Other events having intruded, it has been a week since Part I of my discussion of the question of why Aramaic is still a spoken language (in limited islands) while Coptic is merely a liturgical language among the largest body of Middle Eastern Christians. Part I is here. I hope to get more into the meat of the "why" in this second part, and then in a third part early next week, to address a question that is itself controversial: when, exactly, did Coptic cease to be spoken on a daily basis? Even this has answers ranging from the 14th century on down to the 17th or even later.
Let's begin approximately where we left off. "Coptic" properly refers to that late version of the Egyptian language written in a variant of the Greek alphabet with some letters added from Demotic Egyptian. It emerged in the wake of the Roman conquest of Egypt and, over the next couple of centuries, became transformed in content by Egypt's transformation under Hellenistic culture, Roman administration, and the Christian religion.
Coptic was the spoken language of everyone in Egypt, other than members of the Helleno-Roman administrative elite, but it is worth noting that it was not the language of administration; that was Greek. (Ironically, it took the Muslim conquest for Coptic to become, for a while, the language of administration.) That would seem to have little to do with its survival as a spoken language, but Aramaic was the language of administration in several places, including places (like Iran) that were not even Semitic-speaking. Still, I'm not sure what this might have to do with its survival: people don't generally speak the language of bureaucracy, and this was the golden age of Coptic as a language of theological and religious discourse.
The role of Greek was reinforced at the official level by the split with Rome and Constantinople over the Council of Chalcedon in 451 AD, but the Christological controversy actually reinforced the role of Coptic since the official imperial church was rejected by the Egyptian populace and the Coptic (non-Chalcedonian) patriarchs, sometimes from underground, represented the popular will.
The Arab conquest of Egypt in 632 AD did not at first have much impact on Coptic; in fact it began to replace Greek in administration, though that was short-lived. In 706 AD the Umayyad Caliph ‘Abd al-Malik made Arabic the language of administration. The administration had been dependent on Coptic clerks and secretaries, and to keep their jobs, many Coptic clerks began to master Arabic. In the following Abbasid period, a series of taxpayer revolts by Coptic populations, especially in the central Delta region of Bashmur, led to deportation of the rebels to Iraq and the settlement of Arab tribesmen in the Delta. Up to this time most Arab/Muslims were located in Fustat or other cities, with some tribal groups settling in Upper Egypt. Arabic settlement in the Delta was an important factor in Islamization of the Delta. Or so I argued in a doctoral dissertation a long time ago.
Another major turning point came in Fatimid times with the rule of the bizarre Caliph al-Hakim bi-Amr Allah (996-1020), sometimes characterized as mad for his persecution of Christians but also his exactions on Muslims. Prior to his mysterious disappearance he banned the use of Coptic in public places and even forbade private conversations in the language. Though Hakim's restrictions were limited to a short period, they certainly deterred the daily use of Coptic. Declining education among the clergy, a problem only truly addressed in the 19th century, certainly contributed to the problem.
An external indication of the decline of Coptic is the increasing use of Arabic, even in works with a religious content. Though saint's lives and religious works continued to appear in Coptic, key works seeking a general audience increasingly had to appear in Arabic. The single most important work on church history (and a critical source for the history of Egypt as a whole), the History of the Patriarchs, a compilation of works by many hands, but with the compiling attributed to Sawirus ibn al-Muqaffa (Severus of Ashmunain) in the 10th century, is entirely in Arabic. Even the biographies of early patriarchs which must have originally been written in Coptic, often survive only in Arabic. Another major work, The Churches and Monasteries of Egypt by Abu al-Maqarim (wrongly attributed to "Abu Salih the Armenian" and so translated into English), appeared only in Arabic, in the 13th century. Bilingual dictionaries and wordlists became common, implying that increasing numbers of the faithful no longer spoke or even understood Coptic; already in the 12th century Pope Gabriel II had permitted the use of Arabic in the liturgy and for reading the gospels, because of the decline of Coptic. There are complaints (sometimes attributed to saints of an earlier age) about the decline of Coptic, but little doubt about its reality.
But this is the decline of Coptic as a literary language. The spoken tongue certainly died out more gradually, but when? There is considerable dispute. That it was still spoken in many places in the 14th century seems pretty well established though even that has had its doubters; claims are made for the 16th and 17th centuries and even some outliers for the 19th century. When it died may not be as important as that it died (though as we'll see there were 19th century attempts at revival), but the "when" question will be addressed in Part III early next week.
To the historical sketch above I'd like to add some comparisons with Aramaic which I think help address the "why did one survive and the other is fossilized as a litrugical language?" question:
The Geography: Most of the survivals of Aramaic are found — or were preserved in — mountainous areas; it survived in Tur Abdin in Turkey, in parts of the Kurdish mountains, in the Anti-Lebanon north of Damascus, etc. When it survived in non-mountainous regions it was either a recent introduction (Assyrian refugees from Turkey to Iraqi cities) or there was another geographically isolating factor, such as the Iraqi marshes for the Mandaeans.There are exceptions, but geography was certainly a factor. While there were remote Coptic isolated communities such as the Wadi Natrun or Saint Anthony's in the Eastern Desert, monastic communities obviously cannot reproduce themselves. The Coptic population was located in the Nile Valley and the Fayyum, areas where they were integrated with their Muslim neighbors and the main geographical fact (the River) was a uniting factor.
The lack of speakers beyond the core area, or the broader "installed base". Despite the antiquity of the language and the fact that all Egyptians once spoke it, Egyptian and Coptic were not spoken outside Egypt except by Egyptians abroad, or in a few cases perhaps in the Nubian kingdoms. Aramaic, by contrast, though initially only the native tongue in the Levant, was the lingua franca of the Iranian, Assyrian, Babylonian, and later Seleucid and other successor states across southwest Asia (and liturgically still among India's Saint Thomas Christians), and had currency as far as India and even (in the case of the "Nestorian stele") China. This greater "installed base" provided more speakers across a broader geography, if not more speakers total.
The broader liturgical base. Coptic is the liturgical language of the Coptic Orthodox Church and has some use in the liturgies of the Eastern Orthodox and Roman Catholic churches of Egypt. Aramaic is at least partly the liturgical language of Syrian Orthodox, Antiochian Orthodox, Syrian Catholic, Melkite Catholic, Maronite, Assyrian Church of the East, Chaldean Catholic, Malankara Syriac Catholic, Syro-Malabar Catholic, Malankara Syrian Orthodox, Mar Thoma Syrian Church, and perhaps some I've never heard of; in the Judaic realm it is used in some normative Jewish liturgies, by some Kurdish Jews, as well as in the liturgies of Middle Eastern Karaite Jews and Samaritans (who spoke it until recent centuries); and beyond the Judeo-Christian faiths, it is both the liturgical and to some extent the spoken language of the Mandaeans. For most of these faiths it is preserved only in a limited way in the liturgy and is not a spoken language, and none of the Christian groups rivals the Copts in number, but it is a reminder of how widespread Aramaic was.
Part III will appear early next week.