Old English miere/myre, from Proto-Germanic *marhijō, feminized from *marhaz (horse), from PIE *marko- — a root shared with Old Irish marc and Welsh march, confirming horse vocabulary in the IE homeland. The same root gave English marshal via Frankish 'horse-servant'.
An adult female horse — from Old English miere, Proto-Germanic *marhijō (feminine of *marhaz 'horse'), PIE *marko-, the same root that gave English 'marshal' (literally 'horse-servant').
The modern English word 'mare' (female horse) descends from Old English miere or myre, from Proto-Germanic *marhijō, the feminine form of *marhaz (horse, steed). The masculine *marhaz gave OE mearh (horse, steed) and through Frankish *marh-skalk (horse-servant) entered Old French as mareschal and then English as 'marshal' — a title that rose from stable groom to supreme military commander. The Proto-Germanic root traces to PIE *marko- (horse), a word of enormous cultural significance: the horse was central to PIE civilisation, and the spread of horse domestication across the Pontic-Caspian steppe (c. 3500–3000 BCE) is closely tied to the IE homeland
The word marshal — field marshal, US Marshal, court marshal — literally meant 'horse-servant'. It descends from the Proto-Germanic compound *marhaz (horse) + *skalkaz (servant/groom), which Frankish rulers carried into medieval France as maréchal. The royal stable-groom became the man who managed cavalry logistics, then military command itself. Every marshal in history has carried an unbroken etymological chain back