Thank you so much.
I am exploring every avenue possible but with limited information - not uncommon I know.
It is only from the 1911 U.K. census that Killalla was named as the birthplace of my great grandfather - born 1846.
His marriage certificate names his father as James too - but he is not named on any U.K. Census. His mother, Mary is named and also siblings - Michael, Mary and others I have not had time to investigate.
I know Foley is more a Munster name and I had concentrated my search there until I found Killalla named.
My mother in law ( a Cavan girl ) used to joke that the only Foleys she knew were Mayo sheep stealers. She may well have been right all along. My father in law was a Roscommon boy so he was well acquainted with Mayo people.
Thank you for the links. I will explore.