The 'Stowe Missal', once in the library at Stowe of the Dukes of Buckingham and now kept by the Royal Irish Academy, gives us evidence of the worship of at least one Irish worshipping community in the 790s; it is the earliest surviving Altar Book from this archipelago and also preserves, fossilised, valuable information about the history of the Roman Rite before S Gregory the Great threw the Hermeneutic of Continuity to the winds with his Byzantinising alterations. Stowe reveals that Mass used to begin with a litany; and an anecdote about S Columba suggests that this had been true in his time.
One morning, as his brethren were putting on their shoes to go to work, S Columba stopped them and ordered that they should instead prepare for Mass and for a festal meal. "And I who am so unworthy must today celebrate the sacred mystery of the Eucharist out of reverence for the soul that last night was carried away among the choirs of angels ...". So they did; but the Saint interrupted the litany to tell the singers to add the name of S Colman the bishop [S Colman moccu Loigse] who - so it had been revealed to him - had died that night.
It is well known that legal preliminaries and formal papal pronouncements were not the means by which a man or woman was 'raised to the Altars of the Church' in the early centuries. But I take issue with the assumption sometimes made that canonisation was by acclamation; as if the Church were an ochlocracy in which decisions were made by mobs shouting. The Church has always been a structured, hierarchical body, and the placing of a name on the 'list' or 'canon' of saints must always have been an action formally done by the celebrant of the Eucharist (who in early centuries would of course normatively have been episcopal). So here S Columba does not charge around saying "I've had a vision that Colman is dead"; his monastic brethren do not then start jumping up and down yelling "Goodness how holy he was! Santo subito!" No; S Columba 'canonises' Colman formally by prescibing a Eucharistic celebration on a day on hich this would not normally have happened; summoning his monks to church wearing the white garments they normally wore on major feasts, and then instructing the cantores to name Colman; and that Naming constituted his canonisation.