Saint Patrick (Latin: Patricii) 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, the other patron saints being Brigit of Kildare and Columba. Patrick is venerated as a Saint in the Catholic Church and in the Eastern Orthodox Church, where he is regarded as equal-to-the-apostles and Enlightener of Ireland. He is also regarded as a Saint within the framework of their respective doctrine by the Anglican Communion and the Lutheran Churches. Early medieval tradition credits him with being the first bishop of Armagh and Primate of Ireland, and regards him as the founder of Christianity in Ireland, converting a society practicing a form of Celtic polytheism. According to the autobiographical Confessio of Patrick, when he was about sixteen, 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. 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.