The German name for Austria, Österreich, comes from the Old High German Ostarrichi, which meant "eastern land" and first appeared in a document from 996.

An excerpt from the article 31 facts about Austria

The word is probably a translation of the medieval Latin Marchia orientalis into the local (Bavarian) dialect. Austria was a prefecture of Bavaria, created in 976. The word "Austria" is a Latinization of the German name and was first written down in the 12th century. At that time, the Danube basin in Austria (Upper and Lower Austria) was the easternmost area of Bavaria.