The term "Pen Dragon" also is a Fennian (Ephraimite) form meaning, Pen "child(ren) of" Ap "Son of" combined with "Dargon" or "Dragon" the symbol of the Tuatha de Dannon (Danites) who were warriors that married the Irish widows, hence the Gaullo term Welch (Ue Lach) or "woman of a warrior."
An ancient lineage of Hungarian Shamans evolved out of Egypt. The Dragon cult of Egypt emigrated to Hungary and formed the Royal Court of Dragons. It was from this lineage that the Pendragon family came to England.
http://en.wikipedia.org/wiki/Pendragon