This article considers three languages—Coptic, Latin, and Pehlevi—all of which were widely spoken and written in Egypt in the fourth to seventh centuries, analyzing their use and interaction with Greek, which remained the official language and is by far the most abundantly documented. Each of these languages poses in a distinctive way the problem of multilingualism or of multiliteracy and presents a nuanced picture, ranging from a nearly total and deliberate absence of bilingualism to a deep bilingualism (where the relationship between the languages tends to reverse itself), passing by way of diglossia.