Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The main purpose of this Introduction is to give an account of a movement which changed the whole face of the Irish Church, and to the advancement of which St. Malachy devoted his life. In default of a better word we may call the movement a Reformation, though it might perhaps be more accurately described as an ecclesiastical revolution. Without some knowledge of its aims and progress it is impossible to assign to Malachy his true place in the history of his native country.