A Load of Old ...?

The Cock & The Bull are two old coaching inns in Stoney Stratford. The rivalry between them is thought to have given rise to exaggerated, fanciful traveller's tales, which became known as "Cock & Bull stories".
While possibly true, it has been suggested that this may itself be a cock & bull story, & that the phrase derives from the French "coq-a-l'ane" (from a rooster to an ass), or Cockayne, a medieval term for an imaginary country of luxury & delight.
"Bull" also has the meaning of "a ludicrous self contradiction" (possibly from the old French "Boul", cheat), but doesn't seem to have become "bullshit" until the 20th century.

(I've back-blipped yesterday, so have a look if you'd like. But I warn you, it ain't pretty!)