Editing West Germanic languages (section)

===Dating Proto-West Germanic===
[[File:2022 04 16 - MAP West Germanic – cc. 580 CE - END.png|thumb|West Germanic languages {{circa|580}}{{sfnp |Euler |2022 |p= }}{{page needed |date=May 2025}}]]
If indeed Proto-West Germanic existed, it must have been between the 2nd and 7th centuries. Until the late 2nd century AD, the language of runic inscriptions found in Scandinavia and in Northern Germany were so similar that Proto-North Germanic and the Western dialects in the south were still part of one language ("Proto-Northwest Germanic").

Sometime after that, the split into West and North Germanic occurred. By the 4th and 5th centuries the [[Migration Period|great migration]] set in. By the end of the 6th century, the area in which West Germanic languages were spoken, at least by the upper classes, had tripled compared to the year 400. This caused an increasing disintegration of the West Germanic language and finally the formation of the daughter languages.{{sfnp |Euler |2013 |pp=20-34, 229, 231 }}

It has been argued that, judging by their nearly identical syntax, the West Germanic dialects were closely enough related to have been mutually intelligible up to the 7th century.{{efn |[[Graeme Davis (mediaevalist)|Graeme Davis]] notes "the languages of the Germanic group in the Old period are much closer than has previously been noted. Indeed it would not be inappropriate to regard them as dialects of one language. They are undoubtedly far closer one to another than are the various dialects of modern Chinese, for example. A reasonable modern analogy might be Arabic, where considerable dialectical diversity exists but within the concept of a single Arabic language."{{sfnp |Davis |2006 |p=154 }}}} Over the course of this period, the dialects diverged successively. The [[High German consonant shift]] that occurred mostly during the 7th century AD in what is now southern Germany, Austria, and Switzerland can be considered the end of the linguistic unity among the West Germanic dialects, although its effects on their own should not be overestimated. Bordering dialects very probably continued to be mutually intelligible even beyond the boundaries of the consonant shift.