We gather from an incidental reference during his Welsh journey, that Gildas had a missal written in Greek characters, which he himself had probably got during his sojourn at the Greek monasteries of Marseilles, and he invited Brendan to offer up the Body of Christ on the altar, and make use of this missal. When Brendan saw the strange characters he prayed to God for help, and "sang the Mass from this missal with the Greek characters, even as if they were the Latin letters, which he had known from his infancy." This seems to have taken place at Gildas' monastery of Llancarvan, in South Wales, and it is remarkable that Gildas, David, and Docus, or Cadoc of Llancarvan, are said to have given a new Mass, or Liturgy, to the saints of the Second Order in Ireland. It was perhaps after his return from Britain that Brendan spent some time at the great College of Clonard, and visited the King of Tara. All accounts agree in making the two Brendans--the one of Clonfert and the other of Birr--disciples of St. Finnian of Clonard, who was known as the tutor of the Saints of Erin. This does not imply that Brendan might not himself be quite as old as his tutor, and he probably was so at the time. The saints were not ashamed to become pupils even of younger men than themselves, if they had anything to learn either of knowledge or holiness. It is more likely, however, that he spent his time at Clonard before his sojourn in Britain, and that it was after his return that he visited King Diarmaid at Tara. On this occasion it seems he came to Tara on an errand of mercy, which was destined to have very important consequences.