The word feilire, derived from "feil," the Irish equivalent of "vigils," is applied to the metrical festology composed by AEngus the Culdee about the year 780. It is the most ancient of five martyrologies belonging to Ireland. It consists of three parts: —
(1) Five quatrains invoking a blessing on the poet and his work;
(2) a preface of two hundred and twenty quatrains; and
(3) the festology itself, in three hundred and sixty-five quatrains, for every day in the year.