Patrick was born about 390, in southwest Britain, somewhere between the Severn and the Clyde rivers, son of a deacon and grandson of a priest. When about sixteen years old, he was kidnapped by Irish pirates and sold into slavery in Ireland. Until this time, he had, by his own account, cared nothing for God, but now he turned to God for help. After six years, he either escaped or was freed, made his way to a port 200 miles away, and there persuaded some sailors to take him onto their ship. He returned to his family much changed, and began to prepare for the priesthood, and to study the Bible.
Around 435, Patrick was commissioned, perhaps by bishops in Gaul and perhaps by the Pope, to go to Ireland as a bishop and missionary. Four years earlier another bishop, Palladius, had gone to Ireland to preach, but he was no longer there. Patrick made his headquarters at Armagh in the North, where he built a school, and had the protection of the local monarch. From this base he made extensive missionary journeys, with considerable success. To say that he single-handedly turned Ireland from a pagan to a Christian country is an exaggeration, but is not far from the truth.
Almost everything we know about him comes from his own writings, available in English in the Ancient Christian Writers series. He has left us an autobiography (called the Confessio), a Letter to Coroticus in which he denounces the slave trade and rebukes the British chieftain Coroticus for taking part in it, and the Lorica (or "Breastplate" a poem of disputed authorship traditionally attributed to Patrick), a work that has been called "part prayer, part anthem, and part incantation." The Lorica is a truly magnificent hymn, found today in many hymnals (usually abridged by the omission of the two stanzas bracketed below). The translation into English as given here is by Cecil Frances Alexander, whose husband was Archbishop of Armagh, and thus the direct successor of Patrick. She published nearly 400 poems and hymns of her own, including the well-known "There is a green hill far away," "Once in royal David's city," "Jesus calls us; o'er the tumult," and "All things bright and beautiful, All creatures great and small."
The Propers (link)
The Lorica, or, St. Patrick's Breastplate
The beautiful prayer of St. Patrick, popularly known as "St. Patrick's Breast-Plate", is supposed to have been composed by him in preparation for a major victory over Paganism. The following is a literal translation from the old Irish text:
I bind to myself today The strong virtue of the Invocation of the Trinity:I believe the Trinity in the Unity The Creator of the Universe.
I bind to myself today The virtue of the Incarnation of Christ with His Baptism, The virtue of His crucifixion with His burial, The virtue of His Resurrection with His Ascension, The virtue of His coming on the Judgment Day.
I bind to myself today The virtue of the love of seraphim,In the obedience of angels,In the hope of resurrection unto reward, In prayers of Patriarchs, In predictions of Prophets, In preaching of Apostles, In faith of Confessors, In purity of holy Virgins, In deeds of righteous men.
I bind to myself today The power of Heaven,The light of the sun,The brightness of the moon,The splendour of fire,The flashing of lightning,The swiftness of wind,The depth of sea,The stability of earth,The compactness of rocks.
I bind to myself today God's Power to guide me,God's Might to uphold me,God's Wisdom to teach me,God's Eye to watch over me,God's Ear to hear me,God's Word to give me speech,God's Hand to guide me,God's Way to lie before me,God's Shield to shelter me,God's Host to secure me,Against the snares of demons,Against the seductions of vices,Against the lusts of nature,Against everyone who meditates injury to me, Whether far or near, Whether few or with many.
I invoke today all these virtues Against every hostile merciless power Which may assail my body and my soul,Against the incantations of false prophets, Against the black laws of heathenism, Against the false laws of heresy, Against the deceits of idolatry, Against the spells of women, and smiths, and druids, Against every knowledge that binds the soul of man.
Christ, protect me today Against every poison, against burning,Against drowning, against death-wound,That I may receive abundant reward.
Christ with me, Christ before me,Christ behind me, Christ within me,Christ beneath me, Christ above me,Christ at my right, Christ at my left,Christ in the fort,Christ in the chariot seat,Christ in the poop [deck],Christ in the heart of everyone who thinks of me, Christ in the mouth of everyone who speaks to me, Christ in every eye that sees me, Christ in every ear that hears me.