This book offers a detailed study of the parish priests and senior clergymen of an important Irish diocese over a time-frame that straddles the introduction of the Reformation to Ireland by Henry VIII. It broke new ground with its detailed study of the Irish Church on the ground and revealed, contrary to the assumptions of virtually all historians previously, that the Church in this Irish diocese was in good order on the eve of the Reformation, and showed strong signs of vitality and popular support. The impact of the Reformation in the reigns of Henry VIII, Edward VI and Mary Tudor were traced in unprecedented detail. It showed that the English authorities were able to secure a general acquiescence to a moderated form of Henry VIII's reformation, leaving the Church in parishes under English control with a form of Catholicism without the pope (or religious orders). However, its archbishop, Dowdall, resisted attempts to impose Edward VI's more radical reformation in Armagh diocese, and he co-operated with Queen Mary and Cardinal Pole in restoring Roman authority in Armagh diocese in Mary's short reign. The book did not find evidence that the counter-reformation had become established in Armagh in Mary's reign, though the Catholic Church in Armagh was in a strong position to face Elizabeth's reformation from 1560.