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 caprice made various additions, subtractions and occasional multiplications. The Irish Lives are almost certainly of a somewhat earlier date than the Latin and are based partly (i.e. as regards the bulk of the miracles) on local tradition, and partly (i.e. as regards the purely historical element) on the authority of written materials. They too were, no doubt, copied and interpolated much as were the Latin Lives. The present copies of Irish Lives date as a rule from the sixteenth and seventeenth centuries only, and the fact that the Latin and the Irish Life (where there is this double biography) sometimes agree very perfectly may indicate that the Latin translation or Life is very late. The chief published collections of Irish Saints' Lives may be set down as seven, scil.:--five in Latin and one each in Irish and English. The Latin collections are the Bollandists', Colgan's, Messingham's, Fleming's, and Plummer's; the Irish collection is Stokes' ("Lives of Saints from the Book of Lismore") and the English is of course O'Hanlon's.