Nem great-grandson of Bern. He was called by three names, to wit, Nem and Pupu and Cáilbe. Nem primum nomen etc. Whence Senan of Inis Cathaig sang Abbas almus amabilis etc.
A successor of Peter and Paul, Cailbe came from the east from Rome, Nem, great-grandson of Bern, a bright brother, whose name is Pupu of Aran."
Nennus (Nenus, Nehemias) (St.) Abbot. (June 14) (7th cent. An Irish Saint, the successor of Saint Eudeus in the government of the monasteries of the Isles of Arran and Bute.[3]
Butler's account
The hagiographer Alban Butler (1710–1773) wrote in his Lives of the Fathers, Martyrs, and Other Principal Saints under June 14,
St. Nennus or Nehemias, Abbot
Was of the family of the O'Birns. In 654 he succeeded St. Endeus upon his demise in the government of the great monastery of the isles of Arran, which formerly were two, before the name of Bute was given to one of them. The festival of St. Nennus has been always kept with great solemnity in many parts of Ireland. See Colgan in MSS. ad 14 Jun.[4]