Who was Havell?

Many times you will see the prints of John James Audubon referred to as Audubon/Havells, 'Havell after Audubon', or simply 'Havells.'  Who was Havell?

Robert Havell was a London engraver.  In order to transfer the original watercolor images to copper printing plates, Audubon needed the services of an engraver, someone who with precision tools and chemicals would etch a reverse image of his drawings onto these plates.  The plates would then be inked and pressed upon dampened paper. The paper was then pulled and hand colored by teams of colorists.

William Lizars, also of England, engraved the first ten images supplied by Audubon, but his colorists soon went on strike.  It was Robert Havell who then completed the greater part of the work.