Saint Patrick (Latin: Patricius; Irish: Pádraig ; Welsh: Padrig) was a fifth-century Romano-British Christian missionary and bishop in Ireland. Known as the "Apostle of Ireland", he is the primary patron saint of Ireland, along with saints Brigit of Kildare and Columba. He is venerated in the Roman Catholic Church, the Lutheran Churches, Anglican Communion, the Old Catholic Church and in the Eastern Orthodox Church as equal-to-the-apostles and Enlightener of Ireland.
The dates of Patrick's life cannot be fixed with certainty, but there is broad agreement that he was active as a missionary in Ireland during the second half of the 5th century. Early medieval tradition credits him with being the first bishop of Armagh and Primate of Ireland, and they regard him as the founder of Christianity in Ireland, converting a society practising a form of Celtic polytheism. He has been generally so regarded ever since, despite evidence of some earlier Christian presence in Ireland.
According to the Confessio of Patrick, when he was about 16, he was captured by Irish pirates from his home in Britain and taken as a slave to Ireland, looking after animals; he lived there for six years before escaping and returning to his family. After becoming a cleric, he returned to northern and western Ireland. In later life, he served as a bishop, but little is known about the places where he worked. By the seventh century, he had already come to be revered as the patron saint of Ireland.
Saint Patrick's Day is observed on 17 March, the supposed date of his death. It is celebrated inside and outside Ireland as a religious and cultural holiday. In the dioceses of Ireland, it is both a solemnity and a holy day of obligation; it is also a celebration of Ireland itself.
Two Latin works survive which are generally accepted as having been written by St. Patrick. These are the Declaration (Latin: Confessio) and the Letter to the soldiers of Coroticus (Latin: Epistola), from which come the only generally accepted details of his life. The Declaration is the more biographical of the two. In it, Patrick gives a short account of his life and his mission. Most available details of his life are from subsequent hagiographies and annals, which have considerable value but lack the empiricism scholars depend on today.
Hagiography records other names he is said to have borne. Tírechán's seventh-century Collectanea gives: "Magonus, that is, famous; Succetus, that is, god of war; Patricius, that is, father of the citizens; Cothirthiacus, because he served four houses of druids." "Magonus" appears in the ninth century Historia Brittonum as Maun, descending from British *Magunos, meaning "servant-lad". "Succetus", which also appears in Muirchú moccu Machtheni's seventh century Life as Sochet, is identified by Mac Neill as "a word of British origin meaning swineherd". Cothirthiacus also appears as Cothraige in the 8th century biographical poem known as Fiacc's Hymn and a variety of other spellings elsewhere, and is taken to represent a Primitive Irish *Qatrikias, although this is disputed. Harvey argues that Cothraige "has the form of a classic Old Irish tribal (and therefore place-) name", noting that Ail Coithrigi is a name for the Rock of Cashel, and the place-names Cothrugu and Catrige are attested in Counties Antrim and Carlow.