It is thought that Adomnán may have begun his monastic career at a Columban monastery called Druim Tuamma, but any Columban foundation in northern Ireland or Dál Riata is a possibility, although Durrow is a stronger possibility than most. He probably joined the Columban "familia" (i.e. the federation of monasteries under the leadership of Iona Abbey) around the year 640. Some modern commentators believe that he could not have come to Iona until sometime after the year 669, the year of the accession of Fáilbe mac Pípáin, the first abbot of whom Adomnán gives any information. However, Richard Sharpe argues that he probably came to Iona during the abbacy of Ségéne (d. 652). Whenever or wherever Adomnán received his education, Adomnán attained a level of learning rare in Early Medieval Northern Europe. It has been suggested by Alfred Smyth that Adomnán spent some years teaching and studying at Durrow, and while this is not accepted by all scholars, it remains a strong possibility.