Hi Abm,
Thanks very much for your detailed answer.
Yes, the surname website does seem to suggest a Cornish or Breton link, but my family oral history, since at least my Great Grandfather's time has always suggested a Dutch origin.
Also, my recent Ancestry and FamilySearch research has discovered some Jeggens (eg Israel Jeggens) in Holland in the late 1500s and early 1600s.
I am really stuck on my family tree trying to get further back in time than Thomas Jiggins, b1761 in Essex. I must have an error somewhere or have missed something.
Dank u wel,
David