The Princes of Rhovanion

[Otaku-sempai]

Does the name Éoringas ('horse-folk', sing. Éoring) work for the princes of Rhovanion and their folk before they migrated to the Anduin Vales and called themselves the Leofrings? Éoingas doesn't seem quite right to me; I think the middle consonant 'r' (as in Leofrings) is needed. They still have descendants in the lands of East Rhovanion and the Nether Marches who could be introduced as a variant Culture.

[Majestic]

I have no scholarly knowledge on Linguistics or Philology, but I agree with you, to me Éoringas just sounds better than Éoingas.

[Otaku-sempai]

I have no scholarly knowledge on Linguistics or Philology, but I agree with you, to me Éoringas just sounds better than Éoingas.

Thanks! Also, I think that the region of East Rhovanion is meant to extend all the way south, past the Brown Lands and Dagorlad, to the Ash Mountains. the maps of Journeys & Maps are unclear on this subject. The region south of the Sea of Rhûn to the mountains could be called Southemnet ('south-plain'). The Horse-folk might similarly refer to the Nether Marches of the Dalelands as the North-march. The area between the East Bight of Mirkwood and the Running River might be the Northemnet.

[Earendil]

I'm far from an expert, but my understanding is that the "ing" ending means descendants or possibly family, rather than people as such. The word for "people" is folc.

The Rohirrim call themselves Éothéod, which means "horse-lords", and I'd guess that was what their ancestors called themselves long before settling in Rohan.

Or if you really want "horse-folk" I think it would be Éofolc, but that's probably too similar to Éafolc (the river-folk).

[Otaku-sempai]

Horse-sons vs. Horse-folk. If the Leofrings can collectively call themselves the sons of Leof then who am I to argue? But for their forebears, I can imagine that they called themselves the Éothéod first and named their new home in the Vales of Anduin after themselves. Éofolc would work as well but, as you say, it is too similar to the name of the River-folk. And what's the point in reinventing the wheel?

[Alfgar]

-ing and its plural -ingas (modernized as -ings) is a well attested suffix in both Tolkien's works and Old English literature as a whole, of which poem Widsith is perhaps the best known, and has cognates in other Germanic languages. It does have an alternate form -ling which is thought to be a fusion of the former suffix with a diminutive suffix.
It can be 'translated' as either a patronym (broad or narrow sense) or an ethnonym.
Théoden is referred to as "Thengling" i.e. son of Thengel
Bardings, Beornings, Helmingas and Eorlingas are the (descendents of the) people of each of those individuals.
The problem with Leofring is that C7 has translated the term as the "people of Leof" in the Rhovanion region guide.
Leofring is a name not attested in the surviving corpus of Old English literature. However it is thought by some that the family surname Lovering is the descendent of this hypothetical ancestor.
The linguistic argument is as follows:
Leofring means son of *'Leofr'
*Leofr is a contraction of Leofhere, a name meaning 'dear/beloved-army'. Note that his etymology does fit well with the history of the Leofrings.
There is no -r- attested in any case of the -ing suffix that I know of.

So if we are to adhere to linguistic verisimilitude, 'eoring', euphonic as it may be, does not fit.
Also patronymics of this sort refer to people and not animals, unless of course there was a person named Éo (who of course looks like Richard Harris). Now, having a man named Horse is not something that would be out of place in Tolkien's works.
In Old English, the legendary invaders of England are Hengist and Horsa whose names mean Steed and Horse.
Also, if you believe T.A. Shippey's hypothesis, (and I fervently do) Marcho and Blanco are names meaning horse since those two hobbits are in effect a peaceful Hengist and Horsa.
Another possibility is that your eoring does not mean people of the horse but actually is a contraction of Eoh+here+ing (people/descendents of the horse-army" which becomes eoring by way of syncope and consonant assimilation. This derivation is more linguistically sound and has the benefit of including the term eohere which is the word Tolkien created for the muster of Rohan.

[Glorelendil]

Or if you really want "horse-folk" I think it would be Éofolc, but that's probably too similar to Éafolc (the river-folk).

What would be the pronunciation on those two variants?

[Otaku-sempai]

Tolkien does refer to a Léofa (a.k.a. Brytta) who was the eleventh king of Rohan. Léofa is Rohirric for 'beloved' and was a name bestowed upon him by his people.

If there was a previous Léofa or Leof, I suppose that the remaining horse-folk of the Anduin Vales should be known as the Leofingas (sing. Leoging). Otherwise, as Alfgar states, they should have been united under a leader named 'Leofr'.

[Otaku-sempai]

Or if you really want "horse-folk" I think it would be Éofolc, but that's probably too similar to Éafolc (the river-folk).

What would be the pronunciation on those two variants?

EDIT:

Éofolc = AY-oh-fohlk

Éafolc = AY-ah-fohlk

I think I'll just go with Éothéod of Rhovanion.

[Glorelendil]

Éofolc = AY-oh-fohk

Éafolc = AY-ah-fohk

Pretty subtle difference, although probably not to them. I would go with that name, and then have both groups take major offense to mispronunciation by outsiders. Courtesy roll required to pronounce it correctly.