: Nor any different from the case in late Gaul, when Caesar was running around and talking about their knights, the noblemen who served as his cavalry forces.

: Nobility may imply wealth, and if the horses were supplied by the individual (which would fit with either a feudal Europe model or a classical Gaul model) then the knights would have to be drawn from the wealthier families of the realm.

: I don't believe there were two classes of knights in Gondor, however. It was an embattled realm for much of its history. By Aragorn's day, it was about to wage its last war. Social knighthood doesn't fit well in that environment, especially given Faramir's words to Frodo, where he mentions that the Dunedain of Gondor had become more warlike.

Rome had a very embattled history and its eques became a social class with no connection with military horsemanship. Though the term itself had originated in that class of persons who could afford to go to war mounted in the very earliest days of the Republic when it had a non-professional citizen army. The emperors could grant equestrian status to anyone with sufficient funds to qualify.

If titles give extra authority or social standing they tend to become used through out life. Long after a Gondorain gentleman became to old and fat to serve as a cavalryman do you think he would stop wanting to be addressed as "Sir-knight" or the equivalent?

: I believe that "roquen" would almost certainly exclude someone who was not somehow associated with horses (it is translated as "horseman" rather than "horseperson"). However, the class of knights in Third Age Gondor may have been hereditary (rather than dependent upon appointments and ceremonial qualifications). Occasionally exceptions would be reasonably made, as in Pippin's case.

I don't see the relevance of the distinction between the terms horseman and horseperson here. Terms do undergo modifications of real meaning over time, and can mean more than one thing at any one time. For example in English knight at first meant retainer, then heavily armed cavalryman, and today means either this or "Some aged civil-servant/actor/businessman given a medal and title in the woeful British honours system.

: Isildur's knights may have been "arqueni" (nobles, noblemen) or "arpeni". Words for "warrior" from "The Etymologies" include "mahtar" and "maethor". There is also "ehtar" => "ehtyar", "spearman". "Ohtakaro" is another word for warrior, and it eventually became "Ohtar" (as in "The Disaster of the Gladden Fields"), and Boldog's name contains an element which means "warrior" (Boldog was an Orc captain of the First Age). "herth" is the household of a "hir" (lord), or a troop (of soldiers) led by a "hir".

: Tolkien may have used the term "knight" to refer to an elite warrior associated with the personal retinue of a king or other great leader (a prince or steward). Hence, he might have been disassociating it from the traditional cavalry reference. I don't believe he actually translated "roquen" or any variant as "knight".

Though as he used the English term knight he must have wanted to imbue the knights of his created world with the same (or some of the same) characteristics we associate with the English word. Perhaps some unrecorded Sindarin word was in Tolkien's mind when he used "Knight" - which had a more specific meaning than roquen?

: Other words from "The Etymologies" I should probably throw out for future reference include "haran (pl. harni)" for "king, chieftain", "garon" for "lord", and "aryon" for heir. People should keep in mind that I'm not a linguist, and the languages documented in "The Etymologies" are not exactly the Quenyan and Sindarin of the later books, although there are many carryovers.

: One of the dangers of doing too much research into etymologies, however, is that one can easily assume that a given word is the only representation of an overused English word. For instance, "noble" can mean several things to us: 1) someone born of "high" blood or raised to an elevated social status; 2) something exalted, of greatly admired or desired status or completion; a lofty or noble idea. Tolkien used "arpen" for a nobleperson and "khalle" for "noble, exalted". "weg" gave rise to "gweth", said to mean "man-power", "troop of able-bodied men", "host", "regiment" and an example provided is "forodweith" (Christopher notes this became "forodwaith").

: The implication is that the Elves did not arrive at their vocabularies in the same way we arrived at modern English's vocabulary. Hence, it is erroneous to look for one-to-one correlations between English and Elven words. That is not to say that a word cannot have a direct parallel in English; rather, it seems less likely Tolkien devised such parallels. I suspect much could be deduced of the character and philosophy of the Elves by comparing their etymologies with English etymologies.

In a sense whether roquen was or was not a translation of "Knight" is a side issue, what is important is Tolkien's use of the word knight on the page.