Hi Martin,
I am sorry I haven't replied earlier, I don't check my Ancestry files very often now having reached several road blocks. I have had a lot trouble finding much information about my Irish ancestors. A second cousin of mine I met through Ancestry - our grandmothers were daughters of Thomas and Mary Ann Donohoe - has Luke's father as possibly Richard Byrnes born around 1800. I am not sure now where she found that information. The spelling, I believe, is common in Ireland for a name we might pronounce as Burns. This spelling was we believe was used for Luke and his family in the 1861 census. The various spellings of Donohoe is also a problem. I know Thomas was illiterate, so the spelling found in the census records may or may not be correct. I have had much more success with my dad's side of the family who lived in Yorkshire for centuries. Which of Luke's children - I have 7 in my records - is your ancestor?

Regards,
Irene