An Etymological Dictionary of the German Language/Annotated/Marschall
Marschall, masculine, ‘marshal,’ derived, partly under the influence of French maréchal, from Middle High German marschale, masculine, which literally and originally signified ‘horse-servant,’ then ‘overseer of the train of servants on journeys and expeditions, as a municipal or court official; marshal.’ Old High German marahscalc is a compound of Schalk, ‘servant,’ and marah, ‘horse’; even the Lex Salica and the Leg. Alemannian record the term mariscalus, besides which, in Middle Latin marscallus occurs. From Teutonic are derived the Romance cognates — Italian mariscalco, French maréchal, ‘farrier, marshal,’ as well as the Middle Latin version, comes stabuli, French connétable. Old High German marah, neuter, Middle High German marc, neuter, ‘steed, horse,’ Anglo-Saxon mearh, Scandinavian marr, neuter.; Gothic *marh is wanting. It originated, in exact accordance with the permutation of consonants, from pre-Teutonic marka-, in which form it is recorded as Old Keltic by Pausanias; compare with this Old Irish marc and Welsh march, ‘horse.’ There is, however, no linguistic necessity for deriving Teutonic marha- from Keltic. The word marh, the feminine of which, Mähre, has been preserved, was supplanted at a later period by Roß and then Pferd. To this word Marstall is akin.