Page "Ripuarian Franks" Paragraph 20

The Ripuarian Franks, given an impetus toward social unity by the Roman-administered city of Cologne, must have been speakers of Proto-Germanic.

The extension of an " Old Frankish " to any time before about 500 is anachronistic.

This Frankish unity or the memory of it seems to have lasted well into the period when their range was linguistically divided between High and Low German.

The Old High German began on the eastern part of their range where they bordered on the Alamanni.

The two confederacies were kept distinct by the Romans as long as the latter maintained a base at Mainz.

When it was no longer Roman the sound change spread downstream to Düsseldorf.

Coincidentally the Ripuarian Franks lost their sovereignty to the Salians at about this time.