Here’s what we know about the real St. Patrick.

The modern St. Patrick’s Day celebrations that will take place on Thursday, at least in the United States, will likely be characterised by commercial lucky charms and green beer—all of which has very little to do with the historical figure of the saint.

As it turns out, it took centuries for the holiday to accrue the elements that now seem crucial to its celebrations.

The March 17 celebration started in 1631 when the Church established a Feast Day honoring St. Patrick. He had been Patron Saint of Ireland who had died around the fifth century—a whopping 12 centuries before the modern version of the holiday was first observed.

But very little is known about who he actually was, according to Marion Casey, a clinical assistant professor of Irish Studies at New York University (and a regular marcher in the St. Patrick’s Day Parade in Manhattan).

Read on | Time