In 697 Adomnan, the Abbot of Iona, promulgated a 'law' at the synod held in Birr. This Law, known as the Cain Adomnan or Lex Innocentium, was to protect women, children and non-combatants in warfare, and it was remembered for generations as a significant moment in Irish legal history. Yet today the law, and its author, are barely known.This book consists of three essays on Adomnan by the three foremost authorities on him and his monastery at that time, together with a translation of the law itself.