As the author writes in his preface, The Enemy Within is neither a history nor a biography but an imaginative account of the voluntary exile of St. Columba. Columba, or Columcille, who was born in County Donegal circa A.D. 521. A founder of monasteries, he left Ireland in 563 for Iona where he spent thirty-four years and where the play is set.
Brian Friel concentrates on the private man, a charismatic, worldly personality who struggled to combine skills of scholar, bard and ruler with a fearless commitment to his vocation, and he probes the theme of exile, a subject he returned to in Philadelphia, Here I Come! The Enemy Within is Brian Friel’s first significant play. It remains a neatly accomplished and altogether engaging study.