As one of the dominant languages of the Roman Empire, Greek Koiné continues to play a very important role during the Roman period and shows a big deal of diatopic and diastratal (social and political) variation. One such example is Atticism: the classical language came to be considered as “the ideal variety” as opposed to the administrative Koiné that is dissociated from any literary tradition. Imitating the classical language produced a new literary register referred to as Learned Language, which combines authentic usage with hypercorrect lexical choices and patterns and inevitably shows some effects of Koiné. At the same time, Greek (and Latin) coexisted with numerous other more or less local languages, such as Hebrew, Aramaic, Syriac, Coptic etc. While some of them appear to have become extinct during the Roman imperial times (Etruscan is attested as being spoken for the last time in the 2nd century CE), others not only remained vital, but reacquired more visibility and their own literary tradition in Late Antiquity, and became a crucial facet in the expression of specific regional and religious identities. More generally, the use of language – and specifically, of concrete varieties – is a performative act of enormous relevance in expressing, shaping and reinforcing identity, as well as in claiming belonging or affiliation to specific groups, as sociolinguistic studies (for example, on phenomena such as crossing) have demonstrated. The goal of this conference is to bring together scholars working on different cultural and linguistic aspects of the multilingual society of the Roman Empire, in order to investigate how the Greek language, in its interaction with the other languages written and spoken within the Roman Empire, was deployed and performed as part of a complex cultural discourse and was entangled in the construction of imperial segmentary identities.