[Kransha]

Hmmm, a most interesting topic.

Now, I have not been following as avidly as most the origin thread, so forgive me if ideas I put forth are old hat, but I'll go off anyway. If one is more lenient with the term 'oath' one can get much more out of of it. For example, one might consider the Ban of the Valar an 'oath' taken by the Numenoreans, though they never really took any oath to speak of, it was an oath in the common sense, or lexicon. Therein, the consequences of breaking said oath were most dire. If Ar-Pharazon, the proverbial oath-breaker, had not broken the Ban...well, you know. One of the more cosmic oaths, that one, but of crucial importance, at least in Numenor.

Otherwise, some lesser oaths, and breaking of which, might have also been a revolving theme. Perhaps the theme was more evident in the Silmarillion, but there were other things that could be considered. A great many sections of the Lord of the Rings trilogy, moreso in the second, and most in the final book revolve around swearing oaths of fealty, or changes of allegiance. Again, I refer to being lenient with the term oath. Perhaps an oath of comradery is not the correct oath, but still one. Pippin becoming swearing technical fealty to Denethor is an oath again, and a most interesting one, as it remained unbroken, for Pippin inadvertantly served Denethor even after his dismissal. That is just one simple example, hopefully one that augments your own views. For other, even more conjectural oaths:

One could also call the allegiance of others an oath. For example, the oath-breaking during the Battles of Belerian by the Dwarves, or the oath-keeping of Theoden of Rohan, mustering his Rohirrim and those of his nation to seek out Minas Tirith and defend it from the armies of Mordor. Those are, in some ways, equally important oaths, definately more important in the cosmic sense than individual oaths of fealty, but smaller, more compact oaths are more developing, more enlightening, and hold more importance, character-wise, in my most humble opinion...