Who, in The Lord of the Rings, was the most effective liar?

[Legate of Amon Lanc]

Originally Posted by Eomer of the Rohirrim

Sauron could easily have swayed the Eastern and Southern men to fight for him without lying. Military glory, security from Mordor, crusade against the Western and Northern men; lies were not necessary.

Just for the record, I must react to this - I would side with Prince of Halflings, who has brought up a very good point, I think. There is no indication that the men of the East and South would have been any different in this aspect from the Westerners. They were just more prone to being deceived by Sauron, being sort of further from the light, so to say. Intimidating connected with bribery, yes, as part of any political agreements of such kind, I am sure Sauron tried this on everybody everywhere. But lies were for certain a part of it as well. One big lie itself is if you manage to deceive people into believing that you (as Sauron) are capable of standing against the powers of the West, which, secretly or not, still work in the world in some way. But I am sure the audiences of foreign lords were overflowing with promises of glory, immortality and all this stuff, just like in the good ol' days when the Nazgul were corrupted, mostly from the very same Men. I think the mastery of Sauron's deception was in the fact that the people he was talking to surely knew inside of their hearts that he was lying to them and that the promises he gives are not what they seem, and that they don't lead to immortality (real or metaphorical) and glory, but to death and oblivion. But the people still listened to him and in the end joined him. Isn't that a mastery of deception non plus ultra?

Although I have to join the chorus of those saying that the moments when Sauron's "art" of lie really seems like an "art" are mostly the First/Second Era ones. The episode with Gorlim is definitely the top for me. Sauron (and even more the "proto-Sauron", like his earlier "versions" in the Lay of Leithian) seems to me to be the liar, although of course taking nothing from Morgoth, of whom he was technically a mere servant, so "cosmologically" it is pretty certain that Morgoth was "the" liar; but sort of from the literary perspective, it seems to me that with Sauron, it is somehow more emphasised (and also if the question is only about LotR, then Morgoth is anyway out of question).

[Galadriel55]

If we'd consider the 1st age as well, I'd agree with you on Morgoth. He created lie in the first place. He decieved men, elves, and even the Valar.

[Eomer of the Rohirrim]

Originally Posted by Legate of Amon Lanc

One big lie itself is if you manage to deceive people into believing that you (as Sauron) are capable of standing against the powers of the West, which, secretly or not, still work in the world in some way. But I am sure the audiences of foreign lords were overflowing with promises of glory, immortality and all this stuff, just like in the good ol' days when the Nazgul were corrupted, mostly from the very same Men. I think the mastery of Sauron's deception was in the fact that the people he was talking to surely knew inside of their hearts that he was lying to them and that the promises he gives are not what they seem, and that they don't lead to immortality (real or metaphorical) and glory, but to death and oblivion. But the people still listened to him and in the end joined him. Isn't that a mastery of deception non plus ultra?

Well, Sauron was more than capable of standing up to the Western powers! Why wouldn't the eastern and southern men side with him? Military service and labour as the cost of keeping your family and home safe; far preferable, for most people, than incurring the wrath of the tyrant.

That's why I think these particular 'lies' were not so effective, because the end-result was the same with or without them: those armies were marching for Sauron regardless.