Hi Cathy, This is what is said in part about the Morrissey surname in the following books. The Surnames of Ireland by Edward MacLysaght "This name can be Irish O Muirgheasa (muir, sea - geas, action) or Norman de Marisco..." Irish Families Their Names, Arms & Origins by Edward MacLysaght The O Muirgheasa had their territory near Sligo Bay. The name, Morrissey, is rare and found in Munster - counties 'Waterford, Limerick and Cork. "No Gaelic sept of Morrissey is associated with Munster or Leinster." There was also a Norman family called de Marisco who came to Ireland. The spelling of the name eventually changed to Morrissey. "It is nevertheless reasonably certain that the great majority of Irish Morrisseys are of hibernicized Norman Marisco stock." Perhaps DNA testing will at some point sort this out. I just did a google search and stumbled on this website concerning the de Marisco family. It looks interesting and I haven't read it yet, just skimmed it. Sincerely, Kris (Monigal) Kurtz