The German has spread as a national and official language in the current Germany, Austria and Switzerland; in South Tyrol in 1971 it was formally equated with Italian.
The German group, already in the pre-documentary phase, was differentiated into various dialects; the political affirmation of the Franks (6th century), on Alemanni, Thuringians and Bavarians, determined the extension of a qualifying innovation, on the phonetic level, of the High-German dialectal unit: the ‘second consonant rotation’, which it happens to the first rotation common to the entire Germanic linguistic domain. This innovation (consisting in the passage of deaf, if initial or post-consonant in affricate, if intervocalic in spirant, and from voiced into deaf) extends with decreasing force towards the NW and marks the linguistic limit of the dominion of High German (Hochdeutsch) of opposite the Low-German (Niederdeutsch), which occupies the northern plains of Germany (with Holland and a large part of Belgium) and includes Low-Frankish, Low-Saxon and Low-East German. The High-German domain is divided into two sectors: Upper German, which occupies the southernmost area of the Germany linguistica (with Austria, a large part of Switzerland and Alsace), and Central German, in the remaining territory up to the border linguistic with Low German. The three southern families belong to the first group: upper franc, Alemannic and Bavarian; to the second, the three central families: Middle West Franc, Thuringian and Middle East Franc. In the central area the German literary national language was formed, extended as such also to speakers of Low-German dialects.
The history of the German language is divided into three periods: Old German (6th-12th century), Middle German (12th-16th century), New German or modern literary. Early news, prior to the first literary documentation (8th century), are indirectly provided by classical, literary or epigraphic sources. The first testimonies of the language are from the Merovingian age (Malbergian glosses). The interlinear versions of religious texts and Latin-German glossaries are from the mid-8th century. (Kero glossary, Kassel glossary), as well as the first literary document: the Hildebrand fragment, which shows the progressive prevalence of southern dialectal traits. The factor that most actively contributes, in this phase, to the formation of the language is the influence of the neo-Latin, which manifests itself in the lexicon and in the morphology; two important phonetic innovations are metaphony and the reduction of timbre of the unstressed.
The French influence instead characterizes the middle period: the formation of a unitary, superdialectal literary language of a High-German character is the expression of the chivalric culture, introduced in Germany in the second half of the 12th century, following the French literary and cultural prevalence. But the linguistic unification brought about by chivalric poetry (Minnesang) does not reach popular consciousness; other linguistic forces act in this sense, mainly the jargons of the art guilds, the grammars, the press, the language of the chancelleries. Modern literary German is therefore not the continuation of Middle High German, but results from a leveling between the upper and central dialects, which took place around 1500 in the chancellery of the court of Saxony and enhanced by the unifying work of the Reformation: in fact, Luther chose this language for its translation of the Bible and enabled it to draw upon the broadest strata of the popular masses, thus completing the isolated and varied tendencies towards linguistic unification. Luther’s language, recognized by grammarians (I. Claius, Grammatica Germanicae linguae, 1578) and then became the political and administrative language, reached in the 18th century. a very high literary level with JW Goethe. At the beginning of the 20th century. it had gained its maximum extension, exerting its influence in Hungary, in the Russian provinces of the Baltic and in the African colonies. The two world wars definitively caused its regression in the east.