Many years ago I came across a book on the history of Irish Names. In it the author stated that there were 7 distinct Casey families. It also gave the different coat of arms for each of the families. For example, for the family that came from just outside Dublin, their coat of arms was GREEN(!) instead of the familiar red, which adorns this site ( My personal varient would be purple but let's go there). From memory other families where from Limerick (Hospital/ Bluff area ?), Cork and Waterford. I shall have to dig the book out again.