THE CONCEPT of ‘Anglo-Frisian’ as a common branch on the Germanic language tree was coined in the nineteenth century and appears prominently in the title of Theodor Siebs's (1889) dissertation Zur Geschichte der Englisch-friesischen Sprache (see also Nielsen 1985; Stiles 1995; Hines 2017). Nevertheless, people were already aware of the similarity between Frisian and English much earlier, perhaps even as early as the time of the Anglo-Saxon mission in Frisia in the seventh and eighth centuries. In the late sixteenth century, the language of parts of North-Holland is described as Half Vries, half Engels by woorden ghebroken [‘Half Frisian, half English with broken words’] (Valcooch 1599, fol. A7r), Franciscus Junius, who was an early Old English philologist, visited Friesland in 1646–8 to learn Frisian and study Old Frisian. The Tegenwoordige Staat der Vereenigde Nederlanden [‘The current state of the United Netherlands’] (Schouten et al. 1785), describing Friesland, contains a West Frisian text with a parallel English translation to exhibit the similarities between the languages.

Examples of English-Frisian parallels are easy to find, well known and seemingly convincing. Some older place-names and dialectal words in traditional western Dutch dialects attest to the earlier existence of some form of Anglo-Frisian far beyond the present-day western border of the province of Fryslân (Tab. 12.1).

This paper addresses the following issues. The first part is concerned with the concept of Anglo-Frisian and how it has been critiqued, and subsequently presents a new understanding of the concept. This is made possible by various new results from historical linguistics, including a new interpretation of the early phonological history of English (Versloot forthcoming a; forthcoming b); a close scrutiny of the North Sea Germanic traces in western Dutch (De Vaan 2017); fuller understanding of the earl history of Frisian (Versloot 2014a; Versloot and de Vaan, in prep.); and better access to the dialectal nuances of Old Saxon (Tiefenbach 2010; Versloot and Adamczyk 2017). The second part aims at establishing a link between the linguistic and the archaeological evidence. Special emphasis is put on the spatial organization of the linguistic traces and the actual speakers of these idioms by an analysis of the geographical patterns in the distribution of runic inscriptions, place-names commonly linked to the migration of populations in the Early Middle Ages, and some archaeological artefacts associated with the early Frisians and Anglo-Saxons.