Bannon surname name not usually associated with Cork or Roscommon but there can be exceptions. More likely to be found in Co. Tipperary, Offaly, Westmeath, Longford or Cavan. The christian name Charles does appear in the extinct Bannon family from Ballintubber, Co Longford. See www.irishgenealogy.ar - scroll down , click on B and then Bannon/O Bannon. There is a reasonable chance of finding your ancestor in church records - Charles is the key - not that many of then around. Thanks, Luke Baxter, Longford, Ireland.