Erestor: Appendix A..
Durin's Folk...
'It came to pass that in the middle of
the Third Age Durin was again it's king, being the sixth of that name (the
Dwarves indeed believe that it was Durin himself returned from the death - added by me). The power of
Sauron, servant of
Morgoth, was then again growing in the world, though the Shadow in the Forest that looked towards
Moria was not yet known for what it was. All
evil things were stirring. The Dwarves delved deep at that time, seeking beneath Baranzinbar for
mithril, the metal beyond price that was becoming yearly harder to win. Thus they roused from sleep* a thing of terror that, flying from
Thangorodrim, had lain hidden at the foundations of the earth since the coming of the
Host of the West: a
Balrog of Morgoth. Durin was slain by it, & a year after Nain I, his son; & then the glory of Moria passed, & it's people were destroyed or fled far away.'
*'Or released from prison; it may well be it had already been awakened by the malice of Sauron.'
Quenta Silmarillion; Of The Voyage Of
Earendil & The
War Of Wrath:
'The
Balrogs were destroyed, save for some few that fled and hid themselves in caverns inacessable at the roots of the earth.'
It should be noted that 'some few' is a really poor choice of words, most likely added by Guy Kay and/or Christopher
Tolkien for the published Silmarillion.
HoME states that JRRT Tolkien had determined that the likely total of Balrogs left when Morgoth returned from exile with
the Silmarils was 'three or seven'.....
Therefore, it must be seven. Why?
Gothmog & Ecthelien killed each other; minus one....
Glorfindel and another
Balrog; minus two....
If there is only three, with
Durin's Bane, that leaves zero, and the above quote says 'the Blarogs were ALL destroyed, save SOME FEW.."
So, three is out..
So, with seven, we've already accounted for two, leaving five...
So, if all were destroyed, save some few, what is 'some few' out of 'all destroyed' when there's only five to begin with?
One? Like Durin's Bane?
I'd say that's most likely...
Where would another be hiding unheard of for two
ages if 'the malice of Sauron' awoke DB?
We must remember
The Silmarillion is not to be taken literally word for word, but as traditions handed down for thousands of years & then recorded by
Bilbo......
That's actually the way Tolkien came to realize it.
So no, there's not a couple more Balrogs hiding out there IMHO.
BTW: if you've never read the Appendices at the end of ROTK, A & B contain lots of great info & are a fun read!