An Etymological Dictionary of the German Language/Annotated/ich
ich, pronoun, ‘I,’ from the equivalent Middle High German ich, Old High German ih; corresponding to Old Saxon ik, Dutch ik, Anglo-Saxon ič, English I, Gothic ik. For the common Teutonic ik, from pre-Teutonic egom, compare Latin ego, Ger. ἐγώ, Sanscrit aham, Old Slovenian azŭ, Lithuanian aż. The oblique cases of this primitively nominative were formed in all the Aryan languages from a stem me-; compare mein. The originally meaning of ich, primitively type egom (equal to Sanscrit aham), cannot be fathomed.