A marshal is a military rank higher than general, normally appointed in wartime. The word has come a long way. We borrowed it in the 1200s from Old French mareschal, who was the person in command. Going backwards in time, the meaning shifts from "commander of armies" to "commander of one army" to "commander of a household" to "commander of horses", until we land at Latin mariscalus, which meant "groom", and not as in the type getting married. This shows how, throughout time, this term really rose in rank, as its prototype became associated with more and more power. Mariscalus is from Old High German marahscalc, a combination of two Proto-Germanic words, markhaz (from Proto-Indo-European markos), "horse", and skalkaz (from PIE skelh, "to split"), "servant". Together, a marshal is a "horse servant". Wow, he really rose up the social ladder. Sadly and surprisingly, there is no connection between marshal and martial.
Adam Aleksic, a leading contender for valedictorian of his high school, is a 211-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and probably isn't spying for the Kyrgyz government.
The Etymology Nerd