This chapter is about the evolution of language contact as a research area from the late nineteenth century to the present. It underscores the catalyst part that the discovery of creoles and pidgins by European philologists and other precursors of modern linguistics played in highlighting the roles of population movement and language contact as actuators of language change and speciation. It draws attention to the significance of the study of language evolution in European colonies in making evident the realities of language coexistence. These include the possible competition that can cause language shift and the death of one or some of the coexistent languages, a process that has affected competing European vernaculars faster than it has, for instance, Native American languages. It underscores the expansion of the field as linguists became interested in phenomena such as interference, codeswitching (or translanguaging), codemixing, diglossia, language diasporas, and linguistic areas, as well as factors that facilitate or favor the evolution of structures, sometimes of the same language, in divergent ways, owing to changes in population structures.

It is hardly surprising that contact-based influence on Arabic, with over 300 million native speakers spoken from Uzbekistan to Morocco to northeast Nigeria, has been important. This article walks through eight different historical and cultural stages of contact, beginning with the under-reported story of pre- and early Islamic Aramaic–Arabic contact. Emerging from the shadow of Aramaic to become the dominant language of the Middle East and southern Mediterranean, Arabic left behind interesting minorities in Andalusia (Spain), Malta, and Cyprus, each marked by special sources of influence from Romance languages and Greek, and in the case of Uzbekistan Arabic, pushed to the point of mixed language status by co-territorial Dari and Uzbek. In the Sudanic region, native varieties have undergone profound influence from co-territorial African languages – Kanuri influence is illustrated here – but only in specific domains of grammar. Elsewhere in Africa, contact has been so intense and so compressed that entirely new pidgin-creole varieties (Nubi/Juba Arabic) have emerged. Arabic-internal contact – inter-dialectal and Standard Arabic – constitutes a continuing dynamic within Arabic societies. Arabic represents an open challenge to general theories of contact – Dixon, van Coetsam, Labov – as important to the study of Arabic as to the study of linguistics.