Once Patrick was ordained as a priest and had learned Latin and French, he asked to be sent as a missionary to Ireland, or, as it was known then, Hiberniae, which means the “Land of Winter.” Patrick had a great missionary zeal and soon became Ireland’s second Archbishop of Armagh and Primate of all Ireland.
He set two goals for himself: first, to evangelize the pagan Irish, and second, to set up the ecclesiastical structures and dioceses with a view to achieving independence from Arles, which was supporting the missionary activity in Ireland up until that time.
To do this without modern communications, roads, rail, telecommunications, etc. was very difficult, but Patrick was not deterred by hardship. After all, he was on fire with the love of God in his heart. He knew what his mission would be, and how difficult it was, but he trusted always in the power of God to deliver him, and so he went about evangelizing. He did this by setting up many quasi-monastic structures in towns and villages when he passed through them.
He preached daily about the Kingdom of Heaven and baptized those who accepted the Gospel. Those who excelled in their faith, he ordained to the diaconate, leaving them in charge of the prayer and the various liturgical ceremonies, while in many cases he ordained many devout men to the priesthood.
Later he was able to select from them good and brave men whom he consecrated as bishops with the approval of the Pope. He was also successful in setting up dioceses in larger towns as he journeyed throughout the island of Ireland.
Saint Patrick had laid the foundations not only for the Catholic Church in Ireland but for all of Western Europe and as such deserves the title, yet to be bestowed, of Co-Patron of Europe along with Saint Benedict, Saint Teresa Benedicta of the Holy Cross (Edith Stein), and Saint Bridget of Sweden.
The Irish monks became teachers and inventors. They were, in addition to leading the monastic life of prayer, also great builders and craftsmen. Given that there were so many vocations, they began to look at the possibilities of becoming missionaries not only to Europe but to the Americas.
Many monk missionaries left Ireland well prepared, some bound for Scotland, where they set up a monastery on Iona. Still others went to France, establishing the famous monastery of Locmine in Brittany, which still exists. Others went to Spain and Saint Brendan the Abbot even went to North America (474-577AD).