In Irish traditional history Mug Nuadat (or Mogha Nuadhad) meaning "slave of Nuada," whose given name was Éogan Mór ("Eoghan the Great"), was a king of Munster in the 2nd century A.D. He was a rival of the High King, Conn of the Hundred Battles and for a time after the year 123 was the de facto ruler of the southern half of Ireland. Everything south of a line drawn between Galway Bay and Dublin was known as Leth Moga ("Mug's half"), and everything north of that line was Leth Cuinn ("Conn's half").
Conn later invaded Leth Moga and drove Mug from Ireland. He took refuge in Spain and returned with an army, but was defeated and killed by Conn at Mag Léna (Kilbride , County Offaly) (although in some versions Conn treacherously killed Mug in his bed).
His son was Ailill Ollamh. His grandson, also named Éogan Mór, fought alongside Conn's son Art at the Battle of Maigh Mucruimhe and is credited with founding the Éoganacht dynasty.
