THE Evangelisation of Ireland, mingled as it is with the life of St Patrick, is one of the most surprising facts in the life of the Church in the fifth century. Beyond the limits of the Roman world, the conquest of a whole country was achieved in a few years by the initiative of one man. True, Christianity had become the State religion of the Roman Empire. But Rome had never penetrated into Ireland. Thus, as regards the heathen population of that island, St Patrick found himself confronted with the same situation as were the Apostles in face of the Greco-Roman paganism. The conversion of Ireland was effected during a period when it seemed that civilisation and the new religion must both disappear, swept away by the tide of barbarian invasion. Yet Providence was even then preparing reserves of sanctity and learning, which in Gaul and Italy would, in the seventh century, be the leaven of monastic life and of that of the Christian people. The Apostolic enterprise of St Patrick, if considered from a merely human standpoint, was conducted with rare prudence and skill. The change of religion in Ireland was brought about very rapidly, and without the opposition and persecution which marked the establishment of Christianity in all other countries of the West. This may doubtless be partly explained by the Irish character, and also by the social state of the country, a social state which will be referred to in this volume; but I repeat that it is chiefly due to the intelligent activity of St Patrick that all shock and violence were avoided. We possess only one single work in the French language on the Apostle of Ireland. This is from the pen of M. B. Robert. His Critical Study of the Life and Work of St Patrick is a thesis presented to the Protestant Paculty of Theology for the obtaining of his degree of Bachelor of Divinity. There is much that is good in it, but it is very incomplete. Hence it appears to me that to introduce St Patrick to the public is to present to it the figure of an important, and, as it seems, but little known Apostle.