[radagastly]

Originally posted by Mansun:

Elrond was side by side with Isildur and Elendil during the Last Alliance's stand against Mordor 3,000 years before.

True enough, though I suspect any of his accomplishments were probably eclipsed in the books of lore in Minas Tirith by the presence of Gil-galad, for whom he was the herald. Especially since those books would have to have been written by Isildur:

From The Fellowship fo the Ring, The Council of Elrond:

"Alas! yes," said Elrond. "Isildur took it, as should not have been. It should have been cast then int Orodruin's fire nigh at hand where it was made. But few marked what Isildur did. He alone stood by his father in that last mortal contest; and by Gil-galad only Cirdan stood, and I. But Isildur would not listen to our counsel.

Isildur was the only man to witness the battle, and he had every reason to downplay the role of the any other Elves in whatever lore he may have written about it. He had just defied their advice to destroy the One Ring, which was already preying on his mind, based on the quote from his writing at that time spoken by Gandalf during the Council of Elrond:

and maybe were the gold made hot again, the writing would be refreshed. But for my part I will risk no hurt to this thing: of all the works of Sauron the only fair. It is precious to me, though I buy it with great pain.

In that state, he would have tried his best to keep names like "Elrond" and "Cirdan" at a minimum in any of the histories that he wrote. Such names would lead to questions. Denethor would have very little lore to go on, even if he bothered to study. As Gandalf quoted him:

But unless you have more skill even than Saruman, who has studied here long, you will find naught that is not well know to me, who am master of the lore of this City.

Yet the very next paragraph reveals that there was a great deal of lore that Denethor had never read, including the document about the Ring.