The study originates from the Erlangen research project on word formation in the Middle High German language of documents from the 13th century. It examines in detail the adjective derivation in the texts of the “Corpus of Old German original documents dating to the year 1300” and thus closes a gap in the research, as word formation in German of the High Middle Ages has been little studied to date. This historical period is especially interesting for research purposes because during this period, morphological structures were formed which later became permanently established in New High German.