My name is Alan Jones and, as a Member of the Guild of One Name Studies, I am covering the surname KERNAGHAN and its many Variants, prominent among which is CARNAHAN. 

My mother was a KERNAGHAN from County Antrim, Ireland. From my research into her ancestors over the last 8 years, I have been able to track back her Kernaghan line over four further generations to a James Kernaghan, born about 1797 in Connor, mid-Co Antrim in the Province of Ulster.

The family belief has been that my Kernaghan line originated in Co Donegal but at some point migrated east to mid-Antrim and I have discovered a Census Substitute from the 1660s (Hearth Money Roll) which lists a James and an Alexander Carnekan, both of Connor, Co Antrim. Interestingly, James and Alexander alternate as primary first-born names in my line however I have not been able to bridge back from my James b. 1797 to those two recorded in the 1660s.

At the turn of the 20th Century, the 5 most common Surname variants, in addition to KERNAGHAN itself, were KERNOHAN, KERNAHAN, CARNAGHAN, CARNACHAN and, especially in North America, CARNAHAN.

However there are many more Variants of the surname KERNAGHAN, as exampled by 35 different spellings within the collective Censuses from 1901 for Ireland, Scotland, England and Canada and the 1900 Census for the USA. (see Page  'Surnames"  for more detail).