Welsh history presents its own set of problems for the genealogist. As time changes, the names of places frequently change in response to the social and political pressures of the day. Present day names are often derived from older names. [A change due to language perhaps.] As one climbs out their Welsh family tree, these changes may not be recognized as one goes back in time. For example, the following list shows the present day names of the counties of Wales as compared to the much older Welsh names.
Anglesey (Ynys Mon)
Names are taken from "Welsh Genealogical Research", by Charles M. Franklin, Heritage House, Indianapolis, IN, 1995. p.4.