Browsing the displays of uniforms and insignia at a military museum recently my thoughts soon turned, as usual, to etymology. In particular the military ranks and just why a 'private' seems quite inappropriate.
Marshal - came to English from French, the latter version now seen as marechal and much easier seen as 'stable officer, horse groom' but, as a rank, began in referring to 'an officer in charge of a household' and a rank seen in other languages but, depending on the language group, rather differently. We have already seen the standing for the French, a language of the Latin arm of the Indo-European languages and indeed the Latin languages always have a marshal as a person of importance. Yet when it comes to the other arm of the Western European group, the Germanic tongues, the understanding is quite different. For example the Old English equivalent was a horsthegn, or stable officer - interestingly also the root for the police rank of 'constable' - while Old High German marahscalc 'groom', Frankish marhskalk, Gothic skalks 'servant', and Dutch schalk 'rogue' and very much lower designations.
Commodore - shares an origin with 'commander', both from Old French comandeor, itself the agent noun of the verb 'command'. Tracing the etymology of 'command' we find this to have a common root with 'commend' and 'mandate' in the Latin mandare and ultimately Proto-Indo-European man 'hand' and do 'to give'. Perfectly sensible for one still speaks of 'handing out orders'.
Captain - nothing to do with headgear, this comes from Latin capitaneus 'chief' in the sense of 'prominent'. Taking this back to its ultimate root we find Proto-Indo-European kaput meaning 'head'. Note this is not found in a naval sense until 1560 and no mention in a sporting sense before 1823.
Commander - see 'commodore' above.
Lieutenant - we British traditionally use the pronunciation 'lef-' and have done so since at least the 14th century as evidenced by the documented spelling. Just why this came about nobody has any idea - the Oxford English Dictionary rejects the usual explanation of mistaking the 'U' for a 'V' - but it does call into question a statement I once heard (and often repeat) that "nobody ever mispronounced anything until they could read", it if looks wrong then that is down to spelling. However here this is the exception for judging by every other language where such is used, we Brits have somehow got it quite wrong. Here the rank is made up of two words Old French lieu 'place' and the past participle tenir 'to hold', the latter from Proto-Indo-European ten 'to stretch'. Here the idea is the lieutenant is an officer who often deputises for a higher rank, most often a captain, and thus whilst not translating as such is used in the sense of 'substitute'.
Officer - not used in a military sense until the early 14th century. Clearly from 'office', itself coming to English through the French/Latin route where it literally meant 'work-doing'. and derived from the Proto-Indo-European root op 'to work' and dhe 'to set'. Note this 'office' is the post and not the room, that is unknown before 1560s.
General - used in military sense from 1570s, the noun comes from the adjective and is another coming from the French/Latin source. Here the roots are Latin generalis 'relating to all' and Proto-Indo-European gene 'to give birth' or 'beget'.
Major - has only been a military rank since the 1640s. As a noun it comes from the adjective and again to English from French/Latin. Here Latin magjos is a comparative of magnus 'large, great' and from the Proto-Indo-European root meg 'great'.
Brigadier - seen since the 1670s and another from the French/Latin route, here based on 'brigade', a military division unknown before the 1630s. The Italian brigata means 'troop, crowd, gang' and shares a root with 'brigafe' in brigare 'brawl, fight' and briga 'strife, quarrel. These comparable to Celtic words such as Gaelic brigh and Welsh bri both meaning 'power' and derived from the Proto-Indo-European root dwere 'heavy'.
Colonel - unlike 'lieutenant' (see above), there is an explanation for the pronunciation of 'kernel'. Until the 16th century this appeared as coronel, hence the spelling is wrong as is the norm (see 'lieutenant' above). Middle French coronel, Italian colonnella are both derived from the same root as 'column' or 'pillar'. Here the sense of a solid rectangular formation, albeit tipped on its end, can be traced to the Proto-Indo-European root of kel meaning 'to project, be prominent'.
Admiral - is not seen in its modern sense until the 13th century, and then specifically as amiral de la mer or 'admiral of the sea' which suggests the earlier admirals were not associated with the fleet and this is indeed the case. While 'admiral' came to English from French, for a change this is not Latin but a French loan word of Arabic beginnings. Here the root is a word some crossword puzzlers will be familiar with, for amir is a favourite with American compilers as an alternative (some would say 'correct') spelling for what the British would see as 'emir' and simply means 'commander'. The rank shares its origins with 'admirable', which isn't difficult to see, but the butterfly known as the 'admiral' (named from around 1720) is actually a corruption of 'admirable' and nothing to do with military rank.
Sergeant - seen since the early 13th century, here we go back to the French/Latin trail. Old French sergent meant 'servant' while the Latin servientem referred to 'serving'. Hence we need to find the root of the verb 'to serve' which is simply 'slave'.
Corporal - as the lowest non-commissioned army officer not seen until 1570s, this is another coming from the French/Latin route based on the Latin caput and Proto-Indo-European kaput both meaning 'head'.
Cadet - in a military sense from the 15th century, this shares an origin with 'corporal' (see above) in coming from kaput but here the sense is in 'little head'.
Ensign - seen from the 15th century referring to a flag or pennant, not in the sense of 'rank until 1862, here the word shares a root with 'insignia'. It combines the Proto-Indo-European en 'in' and sekw-no 'to follow', the latter also the root of 'sign'.
Albeit not correctly ranks, I thought it worthwhile also looking at the general terms used in the army, navy and air force of the military.
Solider - has a myriad etymological lines to trace but all essentially mean 'one having pay'.
Sailor - is clearly the agent noun of 'sail, itself traceable to Proto-Indo-European sek meaning 'to cut' and exactly what was required to make a sail from a piece of cloth. Note the term 'sailor' has only been in use since around 1400 (when it was 'sailer'), prior to this it was either 'seaman' or 'mariner'. Looking at these we find 'sea' originally used to mean 'large quantity' and 'man' in the sense 'person' (and thus not sexist in the slightest); while 'mariner' has the ultimate root mori 'body of water'.
Pilot - clearly one could never use this in an aviation sense until the invention of the aeroplane. Earlier balloonists could never be known as 'pilots' as we will see. Many will be aware the use for an airman came from its use in a marine sense, a 'pilot' still steering vessels into harbour, hence this is the sense we need to trace. The term came to English from Middle French pillote, Italian piloto, and Medieval Greek pedotes 'helmsman' and Greek pedon 'steering oar' and all coming from the Proto-Indo-European root ped 'foot'.
Note as the piece is in English, English spelling is used.