In Irish traditional history Eógan (or Eoghan Mór—a name also used by his grandfather, Mug Nuadat), eldest son of Ailill Ollamh, was a 2nd or 3rd century AD king of Munster. He is credited with founding or at least giving his name to the Eóganachta, a dynasty which ruled as kings of Munster and later princes of Desmond until the late 16th century. The son of Éogan Mór was Fiachu Muillethan.