Tadhg Mór Ua Cellaigh

Tadhg Mór Ua Cellaigh, 36th King of Uí Maine and 1st Chief of the Name.

Ua Cellaigh was the first King of Uí Maine to bear the surname Ua Cellaigh, derived from his grandfather, Ceallach mac Finnachta, who was in turn a sixth-generation descendant of Eoghan Finn, a descendant of the first king, Maine Mór.

John O'Donovan recorded a tradition prevalent in the early 19th century concerning Tadhg Mór: "There is a tradition among the O'Kellys of Hy-Many, that they have borne as their crest an enfield, since the time of this Tadhg Mor, from a belief that this fabulous animal issued from the sea at the Battle of Clontarf, to protect the body of O'Kelly from the Danes, til rescued by his followers.

It is also recorded in the Irish annals, that this Tadhg or Teige O'Kelly was chief of Hy-Many in the year 1003 and was slain in the battle of Clontarf, fighting on the side of the monarch, Brian Borumha, 1014, and for this reason he is usually set down in the pedigrees as TADHG CATHA BHRIAIN, i.e., Teige of the Battle of Brian."

His senior descendants in the 21st century are the Counts and Countesses of Grallagh and Tyrcooley, while Kelly is the second most common surname in County Galway, all of whom are direct descendants of Ceallach mac Finnachta.