Despite a lengthy account of his life written by St Adamnan (who died in 702AD), the details of early days of St Columba are somewhat unreliable. He is said to have been of royal descent through both his father and mother and was given a religious education by a priest who became his foster father. He later founded monasteries at Derry, Durrow and Kells. But he fell foul of King Diarmit who had executed a member of Columba's family and had forbidden Columba to retain a copy of a Psalter which he had borrowed. Despite his Latin name "Columba" meaning "dove", he had a fiery temper and instead of turning the other cheek, Columba raised an army and defeated King Diarmit (in 561AD). But for this crime he was excommunicated and as a penance he was told to convert to Christianity as many men as had died in battle - but this had to be carried out away from Ireland.
The Scotii from Ireland had been emigrating across the water to Dalriada (present day Argyll) so it was natural that he should head in that direction. In 563, with 12 companions, he established a monastery here on Iona.
Columba is credited with converting King Bridei (Brude), the leader of the Picts in Highland Scotland to Christianity. This of course helped to strengthen the position of his compatriots, the Scotii in Dalriada. Columba is also said to have persuaded the people of Dalriada to elect Aidan who proved to be a powerful warrior. He died on Iona on 9 June, 597AD.