Eoghan Mor, or Eugene the Great, commonly called Mogha Nuadhad in decent of Heber Fionn, first monarch of Ireland. In the year 122 A.D. at a place called Maynooth he fought a battle with Conn Ceadcatha or Conn of the Hundred Battles, who was the 110th monarch. He was in decent of Heremon, the second monarch of Ireland, younger brother of Heber Fionn. Resulting from this battle, he forced Conn to divide Ireland with him into two equal parts by the boundry of Esker Riada, a long ridge of hills from Dublin to Galway, the south part he termed his and called it after his own
name, Leath Mogha, or "Mogha's Half of Ireland". The northern part was called Leath Cuinn, or Conn's Half, further requiring Conn to give his daughter in marriage to Eugene's son, Olioll Olum. The mother of Olioll Olum & wife of Eugene the Great was Beara, who was the daughter of Heber, King of Castile, Spain.