In about 563 AD, Columba and his followers left Donegal by boat and traveled to the island of Iona off the west coast of Scotland. His mission to Scotland may have been more a case of penance for a battle he may have caused. He refused to return a copy of the Gospels he had copied without permission. He upset the king of Ireland by his refusal, which led to a battle won by his clan. Columba felt remorse over the deaths this caused. Once there he and his monks began the religious conversion of most of Scotland which at that time was pagan. Their fame and influence spread to most of Europe. It became a place of pilgrimage. It also became known as a holy island where 48 kings of Scotland, 4 kings of Ireland and 8 kings of Norway are buried. In 597 Comumba died on Iona. Books on his life began being written a century later. The best known of these was written by Adomnán sometime between 697 and 700. He was proclaimed a saint before the modern process of canonization.