(The). Al Aswad, who set himself up as a prophet against Mahomet. He was called the Weathercock because he changed his creed so often, the Impostor, and the Liar.
Moseilma, another contemporary, who affirmed that the “belly is the seat of the soul.” He wrote to Mahomet, and began his letter: “From Moseilma, prophet of Allah, to Mahomet, prophet of Allah,” and
received for answer a letter beginning thus: “From Mahomet the prophet of God, to Moseilma the Liar.” (Anglo-Saxon, leog-an, to tell a falsehood; but to be recumbent is lieg-an or lig-an.
Prince of Liars. Ferdinand Mendez Pinto, a Portuguese traveller, whose narrative is so much after Munchausen's style, that Cervantes dubbed him “Prince of Liars.” The Tatler called him a man “of infinite adventure and unbounded imagination.”
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Liar from Infoplease: