I have several Dominic or Dominick LEYDENs in my tree. My father was Dominic, his grandfather was Dominic, and his GGrandfather was Dominick. As far as I know, my Leydens originate from Ahamlish in Sligo, but there are several spelling variations of the name: Leyden, Leydon, Lydon, Layden, Leaden. Back then people were relying on the priest or the registrar of births etc. to be able to spell (which often they couldn't)

Jaylay