Gullible was a sea captain?

It has recently come to light that the word ‘gullible’ is derived from a once-famous sea captain ‘Captain Gullible’. The reason we take the word to mean ‘easily led’ nowadays is due to the fact a door-to-door salesman managed to convince him that he could sell him Atlantis, and thereby control of the seas. Of course, everyone knows it’s actually neptune’s trident which awards control of the seas, not the long lost city of Atlantis.