The Irish Times described Frank Duff as 'the founder of the largest international association that has originated in Ireland. Yet he has been, among Irish leaders of his generation, the least publicised.' Duff was not only a major religious figure; he also had a distinct influence on the evolution of modern Irish society. A friend of Irish leaders including Michael Collins, W. T. Cosgrave and amon de Valera, he avoided the cult of celebrity which might well have befallen him as the founder of an organisation which today has over four million active members and ten million auxiliary members in more than one hundred and seventy countries. Like most saintly people, his greatest opposition came from local Church figures and this is a vital part of the story.