Old High German (OHG; German: Althochdeutsch (Ahdt., Ahd.)) is the earliest stage of the German language, conventionally identified as the period from around 500/750 to 1050. Rather than representing a single supra-regional form of German, Old High German encompasses the numerous West Germanic dialects that had undergone the set of consonantal changes called the Second Sound Shift.
At the start of this period, dialect areas reflected the territories of largely independent tribal kingdoms, but by 788 the conquests of Charlemagne had brought all OHG dialect areas into a single polity. The period also saw the development of a stable linguistic border between German and Gallo-Romance, later French.