stylistic:style_transfer, structural:scholar_edition
History

All Germanic languages are thought to be descended from a hypothetical Proto-Germanic, united by subjection to the sound shifts of Grimm's law and Verner's law. These probably took place during the Pre-Roman Iron Age of Northern Europe from c. 500 BC. Proto-Germanic itself was likely spoken after c. 500 BC, and Proto-Norse from the 2nd century AD and later is still quite close to reconstructed Proto-Germanic, but other common innovations separating Germanic from Proto-Indo-European suggest a common history of pre-Proto-Germanic speakers throughout the Nordic Bronze Age.

From the time of their earliest attestation, the Germanic varieties are divided into three groups: West, East, and North Germanic. Their exact relation is difficult to determine from the sparse evidence of runic inscriptions.

The western group would have formed in the late Jastorf culture, and the eastern group may be derived from the 1st-century variety of Gotland, leaving southern Sweden as the original location of the northern group. The earliest period of Elder Futhark (2nd to 4th centuries) predates the division in regional script variants, and linguistically essentially still reflects the Common Germanic stage. The Vimose inscriptions include some of the oldest datable Germanic inscriptions, starting in c. 160 AD.

The earliest coherent Germanic text preserved is the 4th-century Gothic translation of the New Testament by Ulfilas. Early testimonies of West Germanic are in Old Frankish / Old Dutch (the 5th-century Bergakker inscription), Old High German (scattered words and sentences 6th century and coherent texts 9th century), and Old English (oldest texts 650, coherent texts 10th century). North Germanic is only attested in scattered runic inscriptions, as Proto-Norse, until it evolves into Old Norse by about 800.

Longer runic inscriptions survive from the 8th and 9th centuries (Eggjum stone, Rök stone), longer texts in the Latin alphabet survive from the 12th century (Íslendingabók), and some skaldic poetry dates back to as early as the 9th century.

By about the 10th century, the varieties had diverged enough to make mutual intelligibility difficult. The linguistic contact of the Viking settlers of the Danelaw with the Anglo-Saxons left traces in the English language and is suspected to have facilitated the collapse of Old English grammar that, combined with the influx of Romance Old French vocabulary after the Norman Conquest, resulted in Middle English from the 12th century.

The East Germanic languages were marginalized from the end of the Migration Period. The Burgundians, Goths, and Vandals became linguistically assimilated by their respective neighbors by about the 7th century, with only Crimean Gothic lingering on until the 18th century.

During the early Middle Ages, the West Germanic languages were separated by the insular development of Middle English on one hand and by the High German consonant shift on the continent on the other, resulting in Upper German and Low Saxon, with graded intermediate Central German varieties. By early modern times, the span had extended into considerable differences, ranging from Highest Alemannic in the South to Northern Low Saxon in the North, and, although both extremes are considered German, they are hardly mutually intelligible. The southernmost varieties had completed the second sound shift, while the northern varieties remained unaffected by the consonant shift.

The North Germanic languages, on the other hand, remained unified until well past 1000 AD, and in fact the mainland Scandinavian languages still largely retain mutual intelligibility into modern times. The main split in these languages is between the mainland languages and the island languages to the west, especially Icelandic, which has maintained the grammar of Old Norse virtually unchanged, while the mainland languages have diverged greatly.