Code-switching is widely studied within contact linguistics as a symptom of contact or a mechanism of contact-induced change. This research has mainly focused on code-switching in spoken language, and the materials explored have typically been contemporary, though in recent years, code-switching and other multilingual practices have also received increasing attention in historical linguistics. Nonetheless, many historical linguists working on multilingual texts and genres do not seem to think of themselves as contact linguists despite the presence of two or more languages in their research materials.

Although code-switching has moved towards the mainstream of historical language study, little reference is made to code-switching in the written communication of the past in many of the recent handbooks and textbooks of contact linguistics. This chapter addresses this issue by reviewing the role of historical approaches to code-switching in contact linguistics and vice versa, discussing the concept of ‘contact’ with reference to the historical approach (including learned contact through written materials), and seeking to find historical code-switching studies a place within linguistic disciplines. Empirical evidence is sought from the history of English, particularly examples of Latin embedded in an Early Middle or Early Modern English matrix.