[Eorl of Rohan]

Yep. Right on both counts. The passage speaks of the speech of the Rohirrim, rich and rolling yet laden with the sadness of mortal men, which is actually modeled on Old English. The song that Aragorn sings in LOTR, mentioning it as a song of the Rohirrim:

Where now the horse and the rider? where is the horn that was blowing?
Where is the helm and the hauberk and the bright hair flowing?
Where is the hand on the harp-string, and the red fire glowing?
Where is the spring and the harvest and the tall corn growing?
They have passed like rain on the mountain, like a wind in the meadow;
The days have gone down in the West behind the hills into shadow.
Who shall gather the smoke of the dead wood burning?
Or behold the flowing years from the Sea returning?

This is clearly based on this section of The Wanderer, an 8th century Old English Poem:

Where is the horse gone? Where is the rider?
Where is the giver of treasure?
Where are the seats at the feast?
Where are the revels in the hall?
Alas for the bright cup!
Alas for the mailed warrior!
Alas for the splendour of the prince!
How that time has passed away,
dark under the cover of night,
as if it had never been!

I remember reading LOTR in my native language when I was little, and thinking, "Wow. For Mr. Tolkien to praise it so, this 'English' must be such a cool language! Maybe I will learn it someday!" Turns out I did. And probably will continue to learn it for the rest of my life, Eru and the professors willing.

Aaaaaanyway. Well done! It's your turn, Erendis.