IT was in this week of the year 563 that a hugely important development in the history of Scotland took place on the island of Iona.

On the date traditionally held to be May 12, 563, St Columba and 12 companions from Ireland arrived on Iona. At that time only the Kingdom of Dalriada in what is now Argyll and the very southern regions of what is now Dumfries and Galloway were Christian. By the time Columba died in 597, most of the Scottish mainland was Christian, and the Scots – descendants of immigrants from Ireland – and the Picts were united by religion in what historians call the Celtic Church.

We know a lot about Columba because the hagiographic ‘]Life of Saint Columba was written by St Adomnán, ninth Abbot of the Iona monastery, about 100 years after Columba lived.

I have used the translation edited by William Reeves and published in Edinburgh by Edmonston and Douglas in 1874.

Columba was originally Colum, and was later known as Columcille, which means dove of the church.

Tradition has it that he was born into a noble family and studied under St Finnian at Clonard. He was ordained first a monk and then a priest, and became one of Finnian’s 12 Apostles of Ireland, founding monasteries across the northern parts of Ireland. Legends of ancient Ireland say that Columba was the cause of a battle in which many men died, and to make restitution Columba sent himself into exile, travelling to Scotland in a small boat with 12 monks.

The story is that Columba first landed at Southend on Kintyre, but could still see Ireland in the distance, so they sailed onwards to Iona. More likely is that his relative, Conall mac Comhgall, the King of Dalriada, needed priests and monks and gave Iona to Columba in return for pastoral care of his people, the Gaels who originally came from Ulster and had become the Scots.

The National: National Extra Scottish politics newsletter banner

Columba set about building his monastery and making it a school for missionary monks. It immediately became a centre for learning and literacy in a land which was not replete with either, and Columba gained a reputation among the various chiefs of that part of Scotland not just for his piety but his skill at diplomacy.

His own ambition was to convert the Pictish people of the Highlands and islands from Paganism – thought to be of the Druidic variety – to Christianity and while there is evidence that some of the Picts had been converted by individuals such as St Ninian of Whithorn, it was Columba who almost single-handedly brought the Picts into the Christian Church.

He did so by visiting the King of the Picts, Bridei, at his fortress near Loch Ness. The doors of the fortress were reportedly barred against Columba and his monk, but the saint made the sign of the cross and the doors miraculously opened, Bridei converting on the spot.

More likely Columba showed Bridei the advantages of becoming a Christian and having monks from Iona to help him rule his people.

Columba also had a famous encounter with the legendary occupant of Loch Ness. St Adomnán recounted the story, the first mention anywhere of the Monster.

“On another occasion also, when the blessed man was living for some days in the province of the Picts, he was obliged to cross the river Nesa (the Ness); and when he reached the bank of the river, he saw some of the inhabitants burying an unfortunate man, who, according to the account of those who were burying him, was a short time before seized, as he was swimming, and bitten most severely by a monster that lived in the water; his wretched body was, though too late, taken out with a hook, by those who came to his assistance in a boat.

“The blessed man, on hearing this, was so far from being dismayed, that he directed one of his companions to swim over and row across the coble that was moored at the farther bank. And Lugne Mocumin hearing the command of the excellent man, obeyed without the least delay, taking off all his clothes, except his tunic, and leaping into the water. But the monster, which, so far from being satiated, was only roused for more prey, was lying at the bottom of the stream, and when it felt the water disturbed above by the man swimming, suddenly rushed out, and, giving an awful roar, darted after him, with its mouth wide open, as the man swam in the middle of the stream.

“Then the blessed man observing this, raised his holy hand, while all the rest, brethren as well as strangers, were stupefied with terror, and, invoking the name of God, formed the saving sign of the cross in the air, and commanded the ferocious monster, saying, “Thou shalt go no further, nor touch the man; go back with all speed”. Then at the voice of the saint, the monster was terrified, and fled more quickly than if it had been pulled back with ropes, though it had just got so near to Lugne, as he swam, that there was not more than the length of a spear-staff between the man and the beast.

“Then the brethren seeing that the monster had gone back, and that their comrade Lugne returned to them in the boat safe and sound, were struck with admiration, and gave glory to God in the blessed man. And even the barbarous heathens were forced by the greatness of this miracle, which they themselves had seen, to magnify the God of the Christians.”

So many miracles were ascribed to Columba that on his deathbed he was already being described as a saint, and in the Celtic Church there was no rite of canonisation and holy men and women were simply made saints by acclamation. Such was the devotion of the Scots to the saint that Iona became the burial place of Scottish kings.

There are memorials to Columba all over Scotland.