This name is spelled in a great variety of ways. Here we shall adopt the form given in the Felire of Ængus, our oldest and best authority. The nominative there is Moinen, the genitive is Moinend or Moinenn.[186] His festival day, as we know from the same authority, and from all our martyrologies, was the first day of March. As Colgan observes in the sketch which he has given us of this saint, there are some things concerning him which are certain, and some which are doubtful--we should say very doubtful. First of all it is certain that he was the intimate friend and associate of St. Brendan for many years, both during his Atlantic voyages, and when he was founding his monasteries on Lough Corrib's shores and islands. Secondly, he was chosen by St. Brendan from amongst his three thousand disciples to rule over Clonfert, and if he outlived his master, to succeed him in the See and Abbacy. He was in fact a Coadjutor to St. Brendan, chosen by that saint himself on account of his great learning and holiness. Thirdly, it is certain that St. Moinenn after governing Clonfert with great prudence and success, died in the year A.D. 570 or 571, that is six or seven years before the death of Brendan himself. In the scholiast's annotations to the _Felire_ of Ængus, Moinenn is described as "bishop and comarb of Brendan;" and the _Martyrology of Donegal_ calls him at the same date, like all our other Martyrologies--Bishop of Cluain-fearta-Brenainn. The scholiast on Ængus, from the fact that he and St. Senan of Iniscathy are mentioned on the same day, the eighth of March, which is Senan's proper festival, infers that the latter was Bishop Moinenn's psalmist. Now as to what is uncertain, Colgan is inclined to think that this Bishop Moinenn of Clonfert is identical with Monennius, the founder of the great Monastery of Rosnat in Britain, and the master of several of our most distinguished Irish saints, including St. Tighernach of Clones, St. Eugenius of Ardstraw, St. Enda of Aran, and St. Cairbre of Coleraine. It is well known that the prefix _mo_ is merely a term of endearment, and hence the name Moinenn or Mo-nenn, is really the same as Nennio or Mo-nennius, the great and celebrated saint who was undoubtedly the tutor of the saints of Northern Erin, as St. Finnian of Clonard was the tutor of the Saints of the South and West--the celebrated Twelve Apostles of Erin. Colgan's opinion is always entitled to the highest respect, and the more deeply one is versed in the ecclesiastical history of ancient Ireland, the more one is likely to set a high value on the opinion of Colgan. Still we cannot assent to this conjecture of his, especially for reasons of chronology.