My maiden name was POWIS. It comes from the ancient Powys kingdom in Wales where I have heard it pronounced something like "Poe- ees" accent on the ee sound and the s dragged out a bit. Also saw it turned into Powers over here and possibly in Ireland but not Pointon yet. My Powis' were humble iron workersaround Birmingham England probably brought there by Roger de Montgomery the Norman who started mining when given the Black Country by William the Conqueror. Powis castle, relatively modern by Welsh standards and located in Welshpool, Mongomergyshire, Wales is now owned by the herbert family as the Powys line "daughtered out". Hope this is of some use to you if not related to John Charlton specifically!