Island adjacent to the larger island of Mull off the west coast of Scotland. The Irish monk Columba or Colum Cille (c. ad 521–97) founded a monastery here in 563 (see Insular art §1). It became the main religious centre of the kingdom of Dal Riada and head of a confederation of monasteries founded by Columba and his successors in Ireland, in the Pictish territory in eastern Scotland and, from c. 635 to 664, in Northumbria. The internal buildings were of timber, but impressive remains survive of the enclosing bank and ditch. The Life of Columba by Abbot Adomnan (d 704) portrays writing as an important activity in the monastery, and the so-called Cathach of St Columba (Dublin, Royal Irish Acad., s.n.; see Cathach, The), a Psalter with simple penwork decoration, is probably typical of the calligraphy of Iona and its related houses in the late 6th century or early 7th (...