Why do we celebrate St Patrick's Day on 17th March?

It's now associated around the world with Guinness, wearing green, and claiming a bit of Irish ancestry. But the feast day of Saint Patrick, 17 March, should perhaps be a more sombre affair - this after all is considered to be the date of the saint's death. 

While 17 March is the accepted date, the actual year varies and could be 461, 492 or 493. Patrick is generally credited with bringing Christianity to Ireland in the fifth century of the Common Era, though he either followed in the footsteps of Palladius or was one and the same as Palladius - the later Annals of Ulster seem to mix the two.

Muirchú, writing a hagiography in the late seventh century, tells us that an angel came to St Patrick to tell him about his death, and that he shouldn't make his way to his 'beloved' Armagh to die but go to Saul (near present-day Downpatrick and where he perhaps founded his first church after returning to Ireland on his Christian mission).

"Return therefore as I tell you, and you will die and go the way of your fathers.'. (This happened to him on the seventeenth day of March—the years of his entire life numbering one hundred and twenty—as it is celebrated throughout Ireland every year.)

'And you will suspend nightfall.' For on the day of his death there was no night, and for twelve days night did not fall in the province in which his exequies were celebrated, and it did not enfold the earth with its dark wings, and night was not so pale, and Hesperus did not send the shadows which bring along the stars;  and the people of the Ulaid say that to the end of the entire year in which he had deceased the nights were never as dark as they used to be, which beyond doubt happened in order to testify to the merits of so great a man.

From Muirchú's text in English (transl. L. Bieler)

Bede, writing in the eighth century, doesn't mention St Patrick but does tell us that during the eighth year of the reign of Theodosius the Younger, the Roman Pontiff Celestine sent Palladius to the Scots (ie those living on Ireland) who believed in Christ to be their first bishop.

A granite slab in the grounds of Down Cathedral in Downpatrick marks the supposed site of St Patrick's grave, though this stone was only placed in the year 1900. The site itself was promoted as the saint's burial place by an invading Norman knight John de Courcy as part of efforts to consolidate his influence in the area (he claimed to have buried the bones of St Brigid and St Columba here too). Patrick's true burial site is unknown.

Over the centuries, this feast day has evolved beyond remembering Patrick as a holy man, transforming instead into a global celebration of Irish culture and heritage. While Ireland and Northern Ireland mark it as a public holiday, the largest and most vibrant St Patrick's Day celebrations now take place far beyond Ireland’s shores.

Lá Fhéile Pádraig sona daoibh!