Millions of people with Irish heritage across the globe today celebrate Saint Patrick's Day. The country's patron saint introduced Christianity to Ireland around 432 CE, and his passing on March 17, 461 CE, became a day of commemoration in his homeland. While the holiday is steeped in Irish tradition, the festivities have taken on a global flair. The celebration typically includes parades, traditional Irish music and dance performances and indulging in Irish cuisine and beverages. Moreover, wearing green is a fun nod to the Emerald Isle. So, have you pinned a shamrock to your jacket yet?