This is a study of three important late medieval collections of saints' Lives. The manuscripts, written in Latin and, for the most part, relating to the lives of Irish saints, have never before been subject to critical examination. Richard Sharpe's pioneering analysis addresses such questions as when and where the Lives were compiled, and from what sources they derive. Dr Sharpe sets his own treatment of the collections within the wider context of Irish hagiographical studies. Formidable research underpins his lucid exposition and resolution of complex problems of historical and linguistic evidence.