St. Patrick’s Day started as a pretty generic Christian feast day, complete with church services, to honor the Romano-British missionary and later bishop in Ireland that would become Ireland’s patron saint. Importantly Lenten restrictions on alcohol consumption were generally lifted for St. Patrick’s Day, which made it all a little more merry.
Most of our traditions for this holiday come from the Irish diaspora. It served as more of an excuse for Irish folks around the world to generally celebrate their culture. (And, for many, it’s not even a celebration of a culture, but rather a parody of a culture.) So if going to your local St. Patrick’s Day festival feels like equal parts drunken street fair and Irish cultural expo, you’re in the right spot.
The story goes that Saint Patrick would use shamrocks to explain the holy trinity. Big if true, but as with most things involving a saint, it’s almost certainly not. My dude probably lived in the fifth century, and our earliest depiction of him with a shamrock dates to the 1600s. It’s possible that this was an apocryphal tie-in of the triskele and the various triple deities that Irish pagans worshipped; 3s were very important in Irish culture, and shamrocks were kinda abundant.
Three, not four? Shamrocks and clovers are technically not the same thing. That is to say that all shamrocks are clovers, but not all clovers are shamrocks (sort of; they’re all members of the Trifolium genus. Language weirdness: shamrock is meant to mean “young clover” which they absolutely are not, like, baby clovers or something? wtf.) Shamrocks are all green and always have three leaves. Clovers may be green, purple/red (delicious), white or green and white, and some do have four leaves; as this is somewhat rare (and hard to spot), they are considered a token of good luck.
Back to its ties with Saint Patrick! It’s just as likely that the shamrock has to do with Ireland’s ties to the color green. That tradition was cemented in the 11th century or so in The Book of Invasions. The story goes that a descendant of the Gaels had a snakebite healed by Moses himself; the bite promptly turned green, which doesn’t sound too healed to me, but what do I know, I’m only a doctor on weekends. His descendants went on to settle in Ireland, a land that looks oh so verdantly green and is blessedly free of snakes.
Wait, about that. So the tale goes that Saint Patrick himself drove the snakes out of Ireland (with a staff. Not unlike Moses). The earliest mention of AN Irish saint driving the snakes out comes in the eighth-ish century, but it gets tied to Saint Patrick in the eleventh and thirteenth. (Look, I know it’s less practical, but I would be way more into Saint Patrick’s Day if everyone was rockin’ venomous snakes on their lapels. …no?)
In the 1640s, the Catholic Confederation debuted a flag featuring a gold harp on a field of green (very tasteful) during the Eleven Years’ War. Green was long considered a largely Catholic symbol, even though Ireland became known as The Emerald Isle. Some Protestant Organizations in the 18th century (including the Protestant Ascendancy) flew orange flags as a nod to William of Orange, who the Protestants had supported. The three-barred version we know was fashioned in the 1830s as a symbol of solidarity with France (which was going through its second revolution) and a hope for an end to Irish separatism. The flag kinda hung around (ha) in the background until the Irish Free State was established in 1922 when it became their official flag; it then became the flag of Ireland in 1937.
Obviously the flag did not heal that pesky problem of Irish separatism. Many Protestants insist on wearing orange for St. Patrick’s Day even now. (Some people cut the difference an wear an orange wig with their green costume. Healing the world with comedy.)
My personal favorite St. Patrick’s Day tradition is the drowning of the shamrock. At the end of the night, everyone’s last drink gets a shamrock in it. It’s then either thrown over one’s left shoulder… or just drunk down with the rest of the pint. To “wet the shamrock” sometimes means to plan to go out and drink on St. Patrick’s Day, or it can be used to refer to the same tradition.