Saint Patrick’s Day or the Feast of Saint Patrick (Irish: Lá Fhéile Pádraig, “the Day of the Festival of Patrick”) is a cultural and religious holiday celebrated annually on 17 March, the death date of the most commonly-recognised patron saint of Ireland, Saint Patrick (c. AD 385–461).

Much of what is known about St Patrick comes from the Declaration, which was allegedly written by Patrick himself. It is believed that he was born in Roman Britain in the fourth century, into a wealthy Romano-British family. His father was a deacon and his grandfather was a priest in the Christian church. According to the Declaration, at the age of sixteen, he was kidnapped by Irish raiders and taken as a slave to Gaelic Ireland.^[12] It says that he spent six years there working as a shepherd and that during this time he “found God”. The Declaration says that God told Patrick to flee to the coast, where a ship would be waiting to take him home. After making his way home, Patrick went on to become a priest.

According to legend,

Saint Patrick used the three-leaved shamrock to explain the Holy Trinity to Irish pagans.

According to tradition, Patrick returned to Ireland to convert the pagan Irish to Christianity. The Declaration says that he spent many years envangelizing in the northern half of Ireland and converted “thousands”. Tradition holds that he died on 17 March and was buried at Downpatrick. Over the following centuries, many legends grew up around Patrick and he became Ireland’s foremost saint.