A quarrel about a book, we are told, changed his career. He borrowed a Psalter from Finnian of Moville, and made a copy of it, working secretly at night. Finnian heard of the piracy, and, as owner of the original, claimed the copy. Columba refused to let him have it. Then Diarmid, King of Meath, was asked to arbitrate. Arguing that as every calf belonged to its cow, so every copy of a book belonged to the owner of the original, he decided in Finnian’s favour. Columba thought the award unjust, and said so. A little later, after another dispute with Diarmid on a question of monastic immunity, he called together his tribesmen and partisans, and offered battle. Diarmid was defeated. For some reason, not quite clear, these quarrels led to Columba’s voluntary exile (_c._ 563). He sailed from Ireland, and landed upon the silver strand of Iona, and to the end of his days his work lay almost entirely amid the heather-covered uplands and plains of this little island home.[13] Iona became a renowned centre of missionary work, quite over-shadowing in importance the earlier “Scottish” settlement of Whitherne or Candida Casa. Pilgrims went thither from Ireland and England to receive instruction, and returned to carry on pioneer work in their own homeland. Thence went forth missionaries to carry the Christian message throughout Scotland and northern England. Perhaps, too, here was planned the expedition to far-off Iceland. “Before Iceland was peopled by the Northmen there were in the country those men whom the Northmen called Papar. They were Christian men, and the people believed that they came from the West, because Irish books and bells and crosiers were found after them, and still more things by which one might know that they were west-men, _i.e._ Irish.”[14]
Not only to the far north, but to the Continent, did the Irish press their energetic way. In Gaul their chief missionary was Columban (_c._ 543-615), who had been educated at Bangor, then famous for the learning of its brethren. His works display an extensive acquaintance with Christian and Latin literature. Both the Greek and Hebrew languages may have been known to him, though this seems improbable and inconceivable.[15] In his Rule he provides for teaching in schools, copying manuscripts, and for daily reading.[16]