Life of St. Declan of Ardmore and Life of St. Mochuda of Lismore

"[...]     The date or period at which the Lives (Latin and Irish) were written is manifestly, for half a dozen good reasons, a question of the utmost importance to the student of the subject.  Alas, that the question has to some extent successfully defied quite satisfactory solution.  We can, so far, only conjecture—though the probabilities seem strong and the grounds solid.  The probabilities are that the Latin Lives date as a rule from the twelfth and thirteenth centuries, when they were put into something like their present form for reading (perhaps in the refectory) in the great religious houses.  They were copied and re-copied during the succeeding centuries and the scribes according to their knowledge, devotion or [...]".